Neurobiology and Physiology of Behavior
Key Concepts
- Neuroanatomy: Limbic system (amygdala, hippocampus, hypothalamus), prefrontal cortex, basal ganglia, thalamus, and brainstem nuclei. Understand their roles in emotion, memory, motivation, and motor patterns.
- Neurotransmitters: Glutamate (excitatory), GABA (inhibitory), dopamine (reward, motor), serotonin (mood, impulse control), norepinephrine (arousal), acetylcholine (attention, memory).
- HPA axis: Hypothalamic-pituitary-adrenal axis and stress response; cortisol, CRH, ACTH. Chronic stress effects on behavior and health.
- Genetics and epigenetics: Influence of genes on behavior (e.g., breed predispositions), gene-environment interactions.
- Neuroplasticity: Learning and memory processes, critical periods, and the impact of experience on brain development.
Traps
- Confusing the roles of similar structures (e.g., amygdala vs. hippocampus in fear vs. memory).
- Mixing up neurotransmitter functions (e.g., serotonin vs. dopamine in aggression).
- Overlooking species differences in neuroanatomy and physiology.
- Assuming that a single neurotransmitter explains a complex behavior.
Worked Example
A dog with noise phobia shows increased heart rate and cortisol when exposed to thunder. The amygdala triggers fear response via the HPA axis, releasing CRH → ACTH → cortisol. The hippocampus provides contextual memory (previous storms). The prefrontal cortex normally inhibits the amygdala, but under stress, this control may be reduced. Rule of thumb: chronic stress leads to hippocampal atrophy and impaired negative feedback, exacerbating anxiety.