Neurobiology and Behaviour

Embryogenesis

The development of a fully-formed organism from a fertilized egg.

Germ layers

The three initial layers (ectoderm, mesoderm, endoderm) from which all tissues are derived during gastrulation.

Notochord

A flexible rod that develops during gastrulation in chordates and leads to the formation of the neural tube.

Neurulation

The process by which the neural tube is formed in embryonic chordates.

Neural plate

The differentiated cells located in the outer germ layer (ectoderm) that form a plate during neurulation.

Neural tube

The structure formed by the infolding of the neural plate, which will develop into the central nervous system.

Neural crest

The cells flanking the infolded groove of the neural plate that differentiate to form the peripheral nervous system.

Xenopus

A genus of frog with robust embryos that are suitable animal models for studying embryogenesis.

Spina bifida

A birth defect resulting from incomplete closure of the neural tube, leading to exposed spinal cord nerves.

Neurogenesis

The process by which neurons are produced from progenitor neuroblasts.

Synapse

A junction where a neuron transmits a signal to another cell, either chemically or electrically.

Neuroplasticity

The capacity of the nervous system to change and rewire its synaptic connections.

Stroke

The sudden death of brain cells in a localized area due to inadequate blood flow.

Gastrulation

An early phase of embryogenesis where a single-layered blastula differentiates into three germ layers.

Cerebral cortex

The outer layer of tissue in the brain responsible for various functions, divided into four distinct lobes.

Cerebellum

A separate structure at the base of the brain responsible for coordinating unconscious motor functions.

Brainstem

The posterior part of the brain that connects to the spinal cord and controls automatic and involuntary activities.

Hypothalamus

The region of the brain that maintains homeostasis and produces hormones.

Pituitary gland

The "master" gland that regulates other glands and target organs.

Corpus callosum

A bundle of nerve fibers that connects the two cerebral hemispheres.

Animal experiments

Using animals to stimulate or remove brain regions to identify their functions.

Lesions

Abnormal areas of brain tissue that indicate the effect of the loss of a brain area.

Autopsy

A post-mortem examination of a corpse to evaluate causes of death and identify affected brain areas.

fMRI

Functional magnetic resonance imaging, a non-invasive method to identify activated brain areas based on blood flow changes.

Visual Cortex

Located in the occipital lobe, responsible for visual perception.

Broca's Area

Located in the left frontal lobe, responsible for speech production.

Nucleus Accumbens

Involved in pleasure reward pathway, secretes neurotransmitters for pleasure and satiety.

Cerebral Cortex

Outer layer of neural tissue in the cerebrum, involved in memory, perception, consciousness, and thought.

Contralateral Processing

Processing of information on the opposite side of the body.

Corpus Callosum

Bundle of myelinated nerve fibers that facilitate communication between the two brain hemispheres.

Autonomic Nervous System

Controls involuntary processes in the body, divided into sympathetic and parasympathetic pathways.

Pupil Reflex

Involuntary response to regulate the amount of light entering the eye.

Brain Death

Permanent absence of measurable activity in both the cerebrum and brainstem.

Encephalization

Amount of brain mass relative to body mass, higher values indicate higher predicted capacity for intelligence.

Sensitivity

Ability to detect external and internal changes and respond accordingly.

Receptors

Detect stimuli and generate nerve impulses, different types for different types of stimuli.

Human Eye

Sensory organ responsible for vision, consists of various structures for light detection.

Human Ear

Sensory organ responsible for hearing, consists of various structures for sound perception.

Photoreceptors

Rod cells and cone cells in the retina that convert light stimuli into nerve impulses.

Bipolar Cells

Transmit nerve impulses from photoreceptors to ganglion cells.

Ganglion Cells

Transmit nerve impulses to the brain via the optic nerve, involved in visual perception.

Blind Spot

Region in the retina where there are no photoreceptors, resulting in the inability to process visual information.

Contralateral processing

Processing a stimulus on the opposite side to where it was detected.

Optic chiasma

The point where information from each eye may swap, so that the right or left visual field is processed together.

Thalamus

A structure involved in coordinating eye movements and circadian rhythms, and transmits visual information to the visual cortex.

Sound waves

Pressure waves in the air that travel down the auditory canal and cause the eardrum to vibrate.

Ossicles

Three small bones (malleus, incus, and stapes) in the middle ear that amplify sound vibrations.

Cochlea

A fluid-filled spiral tube within the inner ear that converts sound vibrations into nerve impulses.

Vestibular system

A sensory system in the inner ear involved in balance and spatial orientation.

Olfaction

The ability to detect airborne chemicals as scents or smells.

Olfactory receptors

Chemoreceptors embedded in the olfactory epithelium that detect odorant molecules.

Red-green colour blindness

A genetic disorder where an individual fails to discriminate between red and green hues.

Cochlear implants

Devices used to stimulate the auditory centers of the brain in patients with non-functioning hair cells.

Innate behavior

Instinctive responses that are developmentally fixed and independent of environmental context.

Imprinting

Phase-sensitive learning that is rapid and independent of behavioral consequences.

Classical conditioning

Process of behavior modification where desired behaviors become associated with unrelated stimuli.

Reflex conditioning

Placing a neutral signal before a reflex to create an association between the two.

Operant conditioning

Applying reinforcement or punishment after a behavior to increase or reduce its occurrence.

Birdsongs

Communication through songs in birds, involving both innate and learned behaviors.

Memory

The faculty of the mind by which information is encoded, stored, and retrieved.

Encoding

Converting information into a form that can be stored.

Short term memory

Memory with a short recall duration.

Long term memory

Memory with an indefinite recall period.

Presynaptic Neurons

Neurons that release neurotransmitters into the synapse.

Neurotransmitters

Chemical messengers that diffuse into the synapse and bind to receptors on postsynaptic neurons.

Excitatory Post-Synaptic Potentials (EPSPs)

Graded potentials that cause depolarization and generate excitatory signals.

Inhibitory Post-Synaptic Potentials (IPSPs)

Graded potentials that cause hyperpolarization and generate inhibitory signals.

Action Potential

A rapid change in membrane potential that occurs when the combination of excitatory and inhibitory signals reaches a threshold limit.

Summation

The combination of EPSPs and IPSPs in the postsynaptic neuron.

Cancellation

When excitatory and inhibitory graded potentials cancel each other out and no threshold potential is reached.

Spatial Summation

When EPSPs are generated from multiple presynaptic neurons simultaneously to reach threshold.

Temporal Summation

When multiple EPSPs are generated from a single presynaptic neuron in quick succession to reach threshold.

Fast-acting Neurotransmitters

Neurotransmitters that bind directly to ligand-gated ion channels and initiate a rapid response.

Slow-acting Neurotransmitters

Neurotransmitters that bind to G-protein coupled receptors and initiate a slower response.

Neuromodulators

Slow-acting neurotransmitters that can modulate the efficiency of synaptic transfer.

Long-term Potentiation

The strengthening of neural pathways involved in learning and memory through long-lasting changes in synaptic activity.

Stimulants

Drugs that increase neurotransmission levels and enhance psychomotor arousal and alertness.

Depressants

Drugs that decrease neurotransmission levels and slow down brain activities and relax muscles.

Nicotine

A stimulant that stimulates cholinergic pathways by mimicking the action of acetylcholine.

MDMA (ecstasy)

A stimulant that binds to reuptake pumps on presynaptic neurons and blocks the recycling of dopamine and serotonin.

Benzodiazepine

A sedative that binds to GABA receptors and enhances the efficiency of GABA action.

Tetrahydrocannabinol (THC)

A sedative that mimics the neurotransmitter anandamide and blocks the release of inhibitory neurotransmitters.

Anesthetics

Substances that act on ion channels to block the conduction of sensory nerve signals to the central nervous system.

Local Anesthetics

Anesthetics that only affect a localized region by blocking axonal sodium influx.

General Anesthetics

Anesthetics that affect the whole body by blocking calcium influx to prevent neurotransmitter exocytosis.

Endorphins

Endogenous neuropeptides produced by the pituitary gland that function as the body's natural painkillers.

Addiction

A dependence on a substance or activity that results in repeated and compulsive use.

Genetic Predisposition

The influence of specific genes on the rate of drug metabolism or intensity of drug effect.

Social Environment

The impact of prevalent substance abuse, neglect, trauma, culture, and socioeconomic status on addiction.

Dopamine Secretion

The release of dopamine within the limbic system in response to reward, which plays a role in addiction.

Ethology

The scientific study of animal behavior under natural conditions.

Natural Selection

The mechanism of evolution by which the frequency of inherited traits changes as a result of external agents.

Altruism

Behavior that benefits another individual at the cost of the performer, promoting inclusive fitness and kin selection.

Foraging

The act of searching for and finding food resources in nature.

Optimal foraging theory

The theory that animals will adopt strategies that minimize the cost of foraging and maximize the benefits to the consumer.

Selectivity

The behavior of choosing certain types of food sources over others based on their energy yield.

Breeding strategies

Different strategies employed by male coho salmon, such as sneaking or fighting, to successfully reproduce with female coho salmon.

Courtship

Behavioral patterns used by potential mates to inform each other of readiness to reproduce.

Synchronised oestrus

The phenomenon where female lions synchronize their sexual receptiveness to increase chances of survival and reproduction of offspring.

Learned behavior

The process of acquiring new knowledge or skills that can be improved with practice and is dependent on environmental context.