Behavioral Neuroscience Exam 3

Amygdala

Enhances the startle reflex; responds to fear; controls autonomic fear responses; damage reduces fear recognition and prevents PTSD.

Bed nucleus of the stria terminalis

Controls long-term, generalized emotional arousal (long-lasting anxiety).

Prefrontal cortex

Involved in learned behavior, decision-making, and regulating stress responses.

Panic disorder neurotransmitters

Linked to decreased GABA and increased orexin.

Benzodiazepines

Anti-anxiety drugs that bind to GABAA receptors and increase the effects of GABA.

Behavioral Activation System (BAS)

Left hemisphere activity; approach behaviors; linked with happiness and anger.

Behavioral Inhibition System (BIS)

Right hemisphere activity; increases attention/arousal; inhibits actions; linked with fear and disgust.

General Adaptation Syndrome

The three-stage stress response: Alarm → Resistance → Exhaustion.

Alarm stage

Sympathetic nervous system activation; release of epinephrine and cortisol.

Resistance stage

Sympathetic response declines; adrenal cortex releases cortisol to prolong alertness.

Exhaustion stage

Energy resources depleted; weakened immunity.

HPA axis

Stress response route: Hypothalamus → Pituitary (ACTH) → Adrenal cortex (cortisol).

Cortisol

Stress hormone that mobilizes energy.

Chronic stress effects

Weakens immune system and damages the hippocampus.

Classical conditioning

Learning by pairing two stimuli so one predicts the other.

Conditioned stimulus (CS)

Stimulus that produces a response only after pairing with the US.

Unconditioned stimulus (US)

Stimulus that automatically triggers a response.

Conditioned response (CR)

Learned response to the conditioned stimulus.

Amygdala and fear conditioning

Receives sensory input and creates learned fear associations.

Operant conditioning

Behavior followed by reinforcement or punishment.

Reinforcement

Increases likelihood of a behavior.

Punishment

Decreases likelihood of a behavior.

Declarative memory

Explicit memory for facts and events.

Procedural memory

Memory for skills and habits (implicit).

Hippocampus

Critical for forming new declarative memories and spatial memory.

Basal ganglia

Involved in habit learning and gradual, probabilistic learning.

H.M. amnesia type

Severe anterograde amnesia (cannot form new long-term memories).

H.M. abilities intact

Working memory and procedural memory.

Korsakoff's syndrome

Memory disorder caused by thiamine (B1) deficiency; common in alcoholism.

Confabulation

Filling memory gaps with guesses.

Stress and memory

Emotional memories consolidate quickly; chronic stress harms the hippocampus.

LTP (Long-Term Potentiation)

Strengthening of synapses after repeated stimulation.

LTP specificity

Only active synapses are strengthened.

LTP cooperativity

Multiple simultaneous inputs produce stronger LTP.

LTP associativity

Weak input strengthened when paired with strong input.

AMPA receptor

Activated by glutamate and causes depolarization.

NMDA receptor

Opens after magnesium is displaced; allows calcium to enter.

Calcium in LTP

Triggers synaptic strengthening such as added AMPA receptors and dendritic growth.

Sensitization

Increased response to a mild stimulus after exposure to a strong one.

Aplysia

Animal model used to study sensitization.

Serotonin in sensitization

Blocks potassium channels → prolongs transmitter release.

Nucleus accumbens

Central brain region for reward and reinforcement.

Dopamine and addiction

Nearly all addictive drugs increase dopamine in the nucleus accumbens.

Tolerance

Decreased effect of a drug over time.

Withdrawal

Body's reaction when a drug is absent.

Agonist

Drug that mimics or increases neurotransmitter activity.

Antagonist

Drug that blocks neurotransmitter activity.

Major depression key symptom

Absence of happiness.

Bipolar disorder

Alternating episodes of depression and mania/hypomania.

Positive symptoms of schizophrenia

Hallucinations and delusions.

Negative symptoms of schizophrenia

Weak emotion, speech, and socialization.

Panic disorder cause

Low GABA and high orexin.

PTSD symptoms

Distressing recollections, nightmares, strong reactions to stimuli.

Dopamine hypothesis

Excess dopamine (especially D2) causes schizophrenia.

Glutamate hypothesis

Low glutamate activity contributes to schizophrenia.

BDNF

Low levels linked to depression and reduced hippocampal function.

Tricyclic antidepressants

Block reuptake of serotonin, dopamine, and norepinephrine.

SSRIs

Block reuptake of serotonin only.

Antipsychotics (typical)

Block dopamine D2 receptors; treat positive symptoms of schizophrenia.

Atypical antipsychotics

Block serotonin 5-HT2 receptors more than dopamine.

MAOIs

Prevent breakdown of monoamines (dopamine, norepinephrine, serotonin).