As ocean waves move towards shallower waters, they eventually become unstable and break. A breaker zone is a region where waves begin breaking.

Taxonomy is the science of describing, identifying and classifying species. Taxonomic differences, in this context, are differences in the species present.

A community is a group of interacting organisms that live in the same location. Community composition is the makeup of a community

When natural events (i.e. fires, hurricanes or other disturbances) happen to only some areas, scientists can study the effects by comparing affected and unaffected sites. This is a natural experiment.

Development of the layers of the brain.

Caspases are endoproteases (a type of enzyme that breaks down proteins) that play a critical role in both inflammation and cell death.

The presence of caspase 3 and 7 can be used as a sign that cells are preparing to die.

A nucleus whose chromatin has condensed in preparation for apoptosis (programmed cell death)

A nucleus that has started to prepare for programmed cell death (apoptosis)

Cells located in the central nervous system which protect and support neurons in their function.

Glial cells differ from neurons since they do not participate in electrical signaling.

Smaller than what can be seen with a light microscope

In a controlled experimental environment.

Mock NSCs were not infected with Zika.

Real-time polymerase chain reaction, a variant of PCR. It allows for real-time monitoring of DNA amplification and quantification of the product.

https://en.wikipedia.org/wiki/Reverse_transcription_polymerase_chain_reaction

The "multiplicity of infection," which is the average number of virus particles that infect a cell.

Undifferentiated cells in the nervous system that have the potential to develop into any type of cell.

These are differentiated cells which have been reprogrammed into pluripotent ones. This means that they have the ability to develop into any type of cell.

The liquid that surrounds the fetus for its protection, keeping a constant temperature and environment.

An organ that develops only during pregnancy to provide oxygen and nutrients needed for the growth of the baby.

A type of viruses usually spread through mosquito and tick bites. They include West Nile and dengue virus.

In the womb.

The infection of a baby by a virus during a pregnancy.

Such a transmission between the baby and the mother is possible either through the placenta or the birth canal.

Syphilis is a sexually transmitted infection caused by a bacteria known as Treponema pallidum.

Herpes virus infections take place around mouth, lips, genitals, or rectum.

CMV infections spread through contact with body fluids, and often occur in those with weak immune systems.

Rubella is an RNA virus that is normally spread through the air by coughing or breathing.

A disease caused by a parasite called Toxoplasma gondiiand.

It is usually transmitted by eating uncooked food that contains cysts or by exposure to infected cat feces.

Brain injuries

The cause of a disease or disorder.

Diverse

Prevents

A technique that uses a beam of electrons as a light source and has a magnification of up to 1,000,000x (a light microscope's magnification power is 1,500x).

A microscopy technique for seeing cellular components by targeting them in tissue samples.

https://en.wikipedia.org/wiki/Immunocytochemistry

An organ bud (miniature organ) that is anatomically similar to the organ it models. Organoids are used to study organ development and function.

A three-dimensional culture system made up of free-floating clusters of neural stem cells. They are used to study neural precursor cells in vitro.

An abnormally small head due to failure of the brain to grow sufficiently. It is associated with mental disability.

The growth of the brain can be impaired by many genetic and environmental factors, including infections by viruses and genetic syndromes.

![] (http://www.cdc.gov/ncbddd/birthdefects/images/microcephaly-comparison-500px.jpg)

An RNA virus transmitted by mosquitos and sexual interaction with a carrier.

It was first isolated from the Zika Forest of Uganda in 1947. It was previously only known to occur in a narrow range in Africa and Asia. However, in 2015 there was a Zika outbreak in Brazil.

Nonparametric statistical models are often used for data that is ranked.

A covariate is a variable that used in a regression analysis. It is a variable that might be responsible for the outcome of a study, or that might be interfering.

Here, all of the additional variables added in each model were covariates (writing ability, gender, ethnicity, etc.)

The Matthew Effect can be summarized as "the rich get richer and the poor get poorer." It describes the idea that benefits are distributed unevenly, and that those who already have the benefits will continue to accumulate them while those without will not have the chance.

In scientific publication, the Matthew Effect refers to the phenomenon where researchers who are established publish more often simply because they are established (and regardless of the quality of their work).

Regression is a measure of the relation between the mean value of one variable and corresponding values of other variables. There are different types of regression, all of which are used to identify trends in data.

A Poisson regression is a form of regression analysis where we have a random variable, which is equal to the number of events over a period of time if these events are independent and occur at a constant speed.

A principal investigator (PI) is the holder of an independent grant administered by a university and the lead researcher for the grant project, usually in the sciences.

The phrase is also often used as a synonym for "head of the laboratory" or "research group leader."

An applicant's institutional affiliation is the organization that has agreed to be the legal recipient of the grant. This organization can be a nonprofit, a university, or an employer.

The United States Patent and Trademark Office (USPTO or Office) is an agency of the U.S. Department of Commerce which stores, classifies, and disseminates information on patents and gives grant patents for the protection of inventions and to register trademarks.

PubMed is a database of medical and biological publications, created by the National Center for Biotechnology Information (NCBI). It is the free version of the database MEDLINE.

Standard deviation is a statistical measure that is used to describe how much variation there is in a data set. A high standard deviation means that the data is very spread out.

Value-added is the amount by which the value of the product is increased. Here, it means by how much peer review increases new insights about the quality of grant applications.

The impact factor (IF) is a numerical indicator of the "importance" of a scientific journal or article, calculated based on the number of citations and published articles.

The National Institutes of Health (NIH) is an agency of the Department of Health and Human Services and the main agency of the U.S. government responsible for biomedical research and healthcare-related research.

A grant is a money given to enterprises, organizations, and individuals for research, development, and education. Grants do not have to be returned, but most granting organizations require a report about the progress of the outcome.

The Research Project (R01) is a type of grant awarded by the National Institutes of Health (NIH) that provides support for health-related research and development.

Peer-review is the review process for scientific articles, research, or ideas by scientific experts in the same field.

z, F, t and X2 test statistics are parameters that are calculated from a sample and compared with what is expected given the null hypothesis (that there is no effect in reality). The test statistic allows inferences on whether the data allows us to reject the null hypothesis and assume an effect is present.

Cohen's d is a measure for the size of an effect, used to report the standardized difference between two means. It is used to make a judgment if an effect is small (d>0.20), medium (d>0.50) or large (d>0.80).

The Wilcoxon signed-rank test is a statistical procedure that is used on paired data. The test compares the differences between paired data points, ranks the differences by size and considers the direction of the difference by retaining its sign (+ or -), to then allow an inference on whether the mean ranks differ or are the same.

The central tendency of a distribution is captured by its central, or typical values. Central tendency is usually assessed with means, medians ("middle" value in the data) and modes (most frequent value in the data).

Nominal data is the simplest form of data, since it implies no natural ordering between values. For instance, consider subject gender (male and female), which is a nominal variable: neither male nor female comes first, and neither male nor female is larger than the other.

McNemar's test is a statistical procedure for analyzing data that is measured on a nominal scale and where pairs of data points exist. In this example, we have pairs of data points when we consider that each original study and its replication belong together. The test assesses if the outcomes (proportion of significant vs. non-significant results) are the same in the original and the replication studies.

A confidence interval is the range of values in which the true value of the variable of interest would fall, if the experiment were to be repeated again and again. In the case of the 95% confidence interval, the true value would fall in this range in 95% of all cases. Confidence intervals are often referred to with the abbreviation "CI".

A two-tailed test looks for a hypothesized relationship in two directions, not just one. For example, if we compare the means of two groups, the null hypothesis would be that the means are not different from each other. The alternative hypothesis for a two-tailed test would be that the means are different, regardless if the one is bigger or smaller than the other. For a one-tailed test, one would formulate a more specific alternative hypothesis, for instance that the mean of the first group is bigger than the mean of the second group.

Cognitive psychology is a subdiscipline of psychology that studies mental processes like perception, problem solving, attention or memory.

Within-subjects designs vary the predictor in question within each subject: each participant will complete all experimental procedures, in all different conditions. In contrast, between-subjects designs vary the predictor in question between the subjects: each participant completes only one experimental condition.

For example, if a study wanted to test how eating an apple or eating a banana impacts the performance in a subsequent math test, a within-subjects design would have all participants first eat one fruit and complete a test, and then eat the other fruit and complete an equivalent test. A between-subjects design would have half of the participants eat an apple and complete the test, and the other half of the participants eat a banana and complete the test. Some questions are better suited to be studied with a within-subjects design, others are better studied with a between-subjects design.

Covariation indicates how two variables change together, and is the basis needed to calculate a correlation.

Predictors are variables that could affect an outcome of interest.

The null hypothesis is the assumption that a certain effect does not exist in reality, and that any observations of this effect in data is due to error.

Citation impact refers to the importance of an effect deduced from how much of the subsequent body of literature refers to and builds on it by including a reference to the original paper.

Functional magnetic resonance imaging is a procedure that detects the activity of areas in the brain by measuring blood flow.

Macaques are a type of monkeys.

Autism is a mental disorder characterized by difficulties with of social communication and interactions, as well as restricted and repetitive behaviors.

An F-test is a statistical procedure that assesses if the variance of two distributions are significantly different from each other.

A t-test is a statistical procedure that assesses if the means of two distributions are significantly different from each other.

A priori means something was deduced or determined from theoretical considerations, before collecting data.

Selection bias here refers to systematic error in the way studies are included or excluded in the sample of studies which would be replicated. An unbiased selection would be truly random, such that the sample of studies used for replication would be representative of the population of studies available.

A false positive is a result that erroneously indicates an effect exists: although the data suggests an effect exists, in reality, the effect does not exist.

A false negative is a result that erroneously indicates no effect exists: although the data do not suggest that an effect exists, in reality, this effect does exist.

Bias refers to a systematic error or a process that does not give accurate results.

The size of an effect allows us to say whether an effect is big or small, compared to other effects.

An effect is an observed phenomenon, where differences in one circumstance lead to observable differences in an outcome.

Results are referred to as statistically significant when we find the result convincing because it is extremely unlikely to find this data if the effect did not really exist.

An injection into the belly of a mouse that avoids hitting any internal organs.

Mice that do not have the hAPP gene (normal mice).

Wrong or deviating from the norm.

Any extension of a neuron, like an axon or a dendrite.

Wasting away.

Dots or points.

The breakdown of a protein by enzymes.

Ground up or processed tissue.

A molecule that binds to a protein and changes its function.

Cause or origin.

Learning (and remembering) where something is in 3D space.

In this case, the mouse cannot see the platform hidden under the surface of the water. It has to remember from previous trials where it's located.

A maze in which mice learn the location of a platform. The platform is visible at first and then hidden under the water surface once the mice learn its location.

This type of maze requires the hippocampus, one of the first parts of the brain to become damaged in Alzheimer’s disease.

See a video about the Morris Water maze here:

http://www.jove.com/video/897/morris-water-maze-experiment

https://youtu.be/leHLL4vcbCc

Specific genetic mutations that cause Alzheimer’s disease.

These mutations are very rare and only account for about 2% of all cases of Alzheimer’s disease. If an individual has one of these rare mutations s/he is destined to get Alzheimer’s disease (100% chance of developing Alzheimer's).

A set of genes inherited together.

In this case, the authors discuss the idea that several genes related to the tau protein seem to affect the probability that a person will develop Alzheimer’s disease later in life.

This means that molecular changes are made to tau proteins after they are being made.

Some types of abnormal tau appear in cases of Alzheimer’s disease.

Alzheimer's disease is the most common type of dementia. It's a disease of aging in which the proteins amyloid-β and tau build up or aggregate in the brain, causing neurons to die.

Amyloid-β proteins build up into clumps called plaques, and abnormal tau proteins fall off of their microtubules, which kills the neurons. These tau proteins later aggregate into clumps called tangles.

Symptoms of Alzheimer’s disease include memory and cognitive problems, and patients eventually die from the disorder.

This peptide consists of a strand of up to about 40 amino acids that are the main component of the amyloid plaques found in the brains of Alzheimer's patients.

A process in which neurons are damaged or die as a result of too much stimulation (or excitation, hence "excito-toxicity").

For example, excitotoxicity can occur from a seizure.

Mice that have been genetically engineered to produce the amyloid precursor protein, which is thought to give rise to amyloid-β.

Originating from within the body. In this case, "endogenous" refers to the tau proteins that occur naturally in the body of the mice.

A protein that is bound to microtubules.

Microtubules are part of a neuron’s inner cytoskeleton that maintains the structure and stability of the cell.

Tau proteins are primarily found in neurons of the central nervous system.

They stabilize the neuron's microtubules, which are components of the cell's cytoskeleton, the inner stabilizing network of filaments and tubules.

A small protein.

pithing is a method used while preparing specimen for experimental procedures and dissection. It is done by inserting a metal rod into the brain or spinal chord of a living specimen as to kill or immobilise in the least painful way. This method is useful in that it allows for the testing and examination of the physiology of the organs of the prey because they still work, but the animal feels no pain and has no control over their muscles.

Tetanus could refer to the disease caused by a bacterial infection or to rapid/continuous muscle contraction. In this context it is referring to the latter definition;muscle contraction. Each contraction produces an involuntary twitch. Because the electric shocks produced by the electric eel are very frequent the fish ends up constantly twitching with no breaks and no control over its movement .

for more information about muscle contraction; Mann MD (2011). "Chapter 14: Muscle Contraction: Twitch and tetanic contractions". The Nervous System In Action. Michael D. Mann

Cells that carry messages and transmit signals. It is those cells that allow us to perform basic motor functions such as walking, eating, holding things etc.

Is a sturdy alternative to glass. made out of acrylic it is shatter proof as well as sound proof. this is ideal in this experiment because it is clear enough for the eel to se through but does not allow noise or movement of prey to go through, or electric shocks of eel.

jelly like gelatine but made from algae

The connection point between the motor neuron (carrying signal from the spinal chord) and a muscle fibre. This is the communication channel between the two where messages are transmitted using calcium ions. This is necessary to control muscles.

Latency refers to the time thats elapses between an action and a reaction in a system. In this context it refers to the time it takes for the activation of the motor neurone efferents of the prey after the release of the eel electric discharge.

length of a time step of delay

sucking in food (a fish) to catch and eat it, like you suck through a straw

in this context volleys refers to multiple back-to-back electric discharges

While they are referred to as Eels, Electric Eels actually belong to the nocturnal family of knifefish which consists of electric fish that have organs that generate electric current. Eels are the largest Gymnotiformes and use electric current to defend and hunt.

when a neutron is described as being efferent it means that it carries orders away from the central nervous system, which acts like a control centre, towards organs, mainly muscles and glands

This is almost five times more voltage than what you would get out of an Electrical outlet in a US household (120V) and more than twice the voltage of an outlet in Europe (220-240 V)

Location by electricity. In using this tools the eels can explore extreme environment such as muddy water.

mechano referes to mechanical stimulus, which is a physical change such as direct contact, change in pressure or vibration. This change can be sensed by special sensory cells that are found all over the body. These cells allow us to sense vibrations from and contact with other objects.

poison that stops a chemical messenger

electrical cells

Neurotransmitter (molecule, chemical messenger) that takes part in muscular contraction

very strong glue

able to produce a change in the electrical potential of a cell

mechanisms that involve the release of glutamate (a common neurotransmitter)

Humans have chromosomes by pairs. An individual receives one chromosome from each parent. Therefore, he receives two copies of each gene. One says that an individual is homozygous for a certain gene when both of its chromosomes carry the same version of the gene.

Generally PCDH10 belongs to a proto cadherin protein family and it acts as a potential tumor suppressor protein, as the dysregulation of PCDH10 gene frequently existed in multiple human tumors.

PCDH10 is a transcriptional target of p53 and exhibits inhibitory roles in cancer cell motility and cell migration.

The myocyte enhancer factor 2 (MEF2) transcription factor holds together the transcriptional circuits and controls cell differentiation and organogenesis. In adult tissues, Mef2 proteins are also reported to regulate the stress-response during cardiac hypertrophy and tissue remodeling in cardiac and skeletal muscle.

At the beginning of the transcription process, the genetic information of a strand of DNA is copied onto a new molecule, called messenger RNA (mRNA). The mRNA can then exit the nucleus of the cell to be translated into a protein.

This deletion was only present on one chromosome from each parent.

In simplex families, only one person is affected by the disease. Multiplex families have more that one of their members affected by the disease.

A variation of a single nucleotide in a DNA sequence. When less than 1% of a population carries the nucleotide at this position, this variation is classified as a SNP. Some SNPs are associated with certain diseases.

Reminder : Homozygosity Mapping Collaborative for Autism

DNA is a macromolecule forming a long double helical shape and containing the “blueprint” of an organism. It gives the instructions for the production of all the proteins of the organism. Each long portion of DNA is called a chromosome.

Other genes the authors identified are involved in how cells move proteins around. Cells usually do this by packing proteins into endosomes (small spheres made out of membrane) to send proteins to specific places.

A stop codon (or termination codon) is a nucleotide triplet, which stops the synthesis of a protein molecule. It's placed within messenger RNA and signals a termination of translation into proteins.

This termination is taking place due to binding release factors, which cause the ribosomal subunits to disassociate, releasing the amino acid chain.

The set of all messenger RNA transcripts in the considered cell.

Some mutations can affect a neuron's ability to adhere to other neurons. This difficulty can result in autism symptoms.

pertaining to tail.

https://upload.wikimedia.org/wikipedia/commons/6/64/Horse_Axes.JPG

pertaining to spine.

https://upload.wikimedia.org/wikipedia/commons/a/a4/Spinal_column_curvature_2011.png

pertaining to neck.

https://upload.wikimedia.org/wikipedia/commons/a/a4/Spinal_column_curvature_2011.png

the underside or the abdominal part of the body https://upload.wikimedia.org/wikipedia/commons/6/64/Horse_Axes.JPG

an anatomical term which refers to a bone called humerus

https://upload.wikimedia.org/wikipedia/commons/e/e4/Humerus_-_anterior_view.png

an anatomical term which refers to a bone called femur![]https://upload.wikimedia.org/wikipedia/commons/8/8f/Femur_-_anterior_view2.png

https://upload.wikimedia.org/wikipedia/commons/8/8f/Femur_-_anterior_view2.png

pertaining to side or sides.

https://upload.wikimedia.org/wikipedia/commons/3/34/Anatomical_Directions_and_Axes.JPG

any kind of cell that secretes sebum- an oily substance which contains fat-

a population that fits into a larger one!

https://upload.wikimedia.org/wikipedia/commons/4/41/Floral_matryoshka_set_2_smallest_doll_nested.JPG

the outer layer that mainly serves as protection

to change to a form that contains keratin- a fibrous protein which mostly found in hair, nail, hoof, etc.-

superposing means to put or lay something over something else

pertaining to histology-the science of studying tissues-

As you know from molecular biology, protein-coding region of DNA transcribe into mRNAs and then, mRNAs, in their turn, translate into proteins on ribosomes. Basically three nucleotides are required to code for any aminoacid, so the part of mRNA that translates into proteins has a "frame" which is divisible by three; if a deletion cause removal of three or a multiplicate of three then the frame will stop at the previous stop codon and other aminoiacs remain untouched, otherwise the deletion may turn the protein to anything at all.

https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/RNA-codons-aminoacids.svg/2000px-RNA-codons-aminoacids.svg.png

homologous properties in biology have the same evolutionary origins but not necessarily a same function. like human and bat's arm.

https://upload.wikimedia.org/wikipedia/commons/5/5b/Evolution_pl.png

http://www.publicdomainpictures.net/pictures/10000/velka/2185-1265152109AYHt.jpg

https://upload.wikimedia.org/wikipedia/commons/2/2c/Extant_reptilia.jpg

covered with scutate-A horny or bony external plate.!

https://upload.wikimedia.org/wikipedia/commons/1/17/Alligator_foot_detail.jpg

A sequence of species that have evolved from a same ancestor.

a sequence of species that have evolved from a same ancestor.

https://upload.wikimedia.org/wikipedia/en/6/68/Diagram_of_Eusocial_Species.png

sections that are made in a cryostat- a device for keeping the temperature low-.

A protein of DNA polymerase delta. it is involved in the control of eukaryotic DNA replication. PCNA is important for replication and participates in cell division. so it's present in cell shows that the cell is proliferating.

an imaginary plane that divides the body into right and left halves.

A group of chemicals that are growth factors.

An area of tissue that joins the epidermal (outer layer) and the dermal layers (middle layer) of the skin.

Elevations refer to bumps found in this layer, leading to areas that are slightly raised.

https://upload.wikimedia.org/wikipedia/commons/e/ec/Anatomy_of_the_skin.jpg

Cell's shape that are similar to the columns and it's height is at least four times their width.

https://upload.wikimedia.org/wikipedia/commons/c/c5/Simple_columnar_epithelial_cells.png

On of the principles of darwin's Evolutionary theory that says organisms share a most recent common ancestor.

https://upload.wikimedia.org/wikipedia/commons/thumb/7/70/Phylogenetic_tree.svg/2000px-Phylogenetic_tree.svg.png

An imaginary plane that divides the body into right and left halves.

Not happening at the same time

Refers to a group of molecules in a cell that work together to control one or more cell functions.

The tumor necrosis factor (TNF) superfamily : a group of cytokines that take place in apoptosis.(cell death)

Two alleles of a gene in a heterozygote that are both fully expressed.

Tooth fused to the inner edge of the jaw.

This means it is loosely attached and can regenerate if it is lost.

futherest part of the limb, such as the hand or foot.

A structure or system with an original function evolves so that the it adds or changes to a new function.

A small spherical group of cells containing a cavity in which materials are contained and can grow.

Example: hair, teeth, feathers

In biology, similarity of the structure, physiology, or development of different species of organisms based upon their descent from a common evolutionary ancestor.

Basically, in biology each cellular function achieves by corporation of protein complexes; for example in mammals, DNA replication happens by DNA polymerase and a dozen of other molecules( for example PCNA); so if we recognise any of these molecules that make DNA replication happens; it shows that the cell is proliferating;

A type of the typical form of a species in which seen in nature.

Relating to, or characteristic of birds.

A platelike structure, especially a thickening of the ectoderm marking the site of future development in the early embryo

The order Squamata, or the scaled reptiles, are the largest recent order of reptiles, comprising all lizards and snakes.

A biological process in which embryo develops to adult in some organisms.

A transitional fossile that gives us information about a transition from one species to another. Actually is one that falls between "before transition forms" and "after transition forms"

Life form that is currently in existence.

Antonym: extinct

DNA (which stores genetic information) makes RNA (which transports genetic information) which is then read to make a protein which is functional

cDNA is a copy of the RNA which is tells us what protein will be created.

A genetic disease which affects the growth of hair, teeth, nails and sweat glands.

A statistical test that is used to determine if two sets of data are significantly different from each other.

The probabilistic algorithm is algorithm that, providing circulation on the certain stages of its work to the random number generator in order to obtain savings in work time.

A correlation describes how two variables are linked one to the other.

The National Science Foundation (NSF) is an independent agency of the U.S. government that is responsible for the development of science and technology. The Foundation carries out it's mission by providing, in general, temporary grants.

A piece of equipment used to record and identify high frequency calls beyond the range of human hearing.

These detectors have a frequency dial. Once a frequency is chosen, the detector only detects sounds at that frequency. Because the dial was set at 23 kHz, sounds far above or below that frequency would not be detected.

http://www.batbox.com

Used to describe sounds at a frequency above the human hearing range.

Empathic concern (identifying with the emotions of another person) in humans is thought to be hard-wired into our brains. It becomes evident as early as age 2 and is dependent on our social interactions.

There are several contributors to empathy including:

(A) Shared neural representations (activity in the brain in response to an experience in your environment). For example, the neural networks that are active when you feel sad would also be active when you see someone else expressing sadness and feel empathy for them.

(B) Self-awareness (conscious knowledge of one's own character, feelings, motives, and desires).

(C) Mental flexibility, or the ability to shift a course of thought or action according to the changing demands of a situation. It allows an individual to abandon a previous response set or pattern in order to generate an alternative that is better suited to the requirements of the situation at hand.

(D) Emotion regulation, or the ability to respond to the ongoing demands of an emotional experience in a manner that is socially tolerable and sufficiently flexible to permit spontaneous reactions.

A single-nucleotide polymorphism is a variation in a single nucleotide at a particular location in the genome.

The authors are referring to a position in the human BDNF gene. Variation in the DNA sequence at this position is associated with a reduced ability to recall extinction.

Genetic knockdown is a technique that researchers use to reduce the expression of specific genes in order to study their function.

Based on previous research (see references 14–16), the authors chose to test the amygdala and hippocampus because they were the most likely contributors of BDNF to the IL mPFC.

When something is said to occur "in vitro," it means that it has been tested or observed in parts of an organism that have been removed from their original biological surroundings.

Examples include most studies done in test tubes or petri dishes, where some tissues or cells are isolated so they can be studied more carefully.

When something is said to occur "in vivo," it means that it has been tested or observed in whole, living organisms.

A receptor antagonist is a drug or compound that can bind a receptor and inhibit its activation.

A type of learning where repeated presentation of a stimulus leads to a decrease in response. If you put an animal into a new environment for behavioral testing, the animal may become agitated or fearful.

However, if you expose the animal to that environment a few times before the experiment begins, the animal will not be as nervous because it has been “habituated” to the testing environment.

Pre-exposure to a stimulus can make it difficult to form new associations with that stimulus. In other words, it takes longer for a familiar stimulus to acquire meaning than a new stimulus.

In this case, the authors wanted to see whether BDNF was changing freezing behavior by enhancing the effects of habituation trials.

BDNF does not appear to enhance the process of latent inhibition.

The authors performed additional behavioral tests in order to rule out nonspecific behavioral effects of the BDNF injection.