BAPSY Biological Bases of Behavior 5 — Questions and Answers
Question 1: Which neurotransmitter is released at the neuromuscular junction to trigger muscle contraction?
- Dopamine
- Norepinephrine
- Acetylcholine (Correct answer)
- Glutamate
Correct answer: Acetylcholine
Motor neurons release acetylcholine (ACh) at the neuromuscular junction, which binds nicotinic receptors to initiate muscle contraction.
Question 2: Damage to the amygdala most consistently impairs which psychological function?
- Language comprehension
- Spatial navigation
- Fear conditioning and threat detection (Correct answer)
- Fine motor coordination
Correct answer: Fear conditioning and threat detection
The amygdala is critical for acquiring and expressing conditioned fear responses, as demonstrated by the famous case of patient S.M.
Question 3: In split-brain research, if an image is presented only to the LEFT visual field, it is processed by which hemisphere?
- Left hemisphere
- Right hemisphere (Correct answer)
- Both hemispheres equally
- The cerebellum
Correct answer: Right hemisphere
The left visual field projects to the right hemisphere via the optic chiasm, where nasal fibers cross and temporal fibers stay ipsilateral.
Question 4: Which structure in the midbrain contains dopamine-producing neurons whose degeneration causes Parkinson's disease?
- Locus coeruleus
- Raphe nuclei
- Substantia nigra (Correct answer)
- Ventral tegmental area
Correct answer: Substantia nigra
The substantia nigra pars compacta houses dopaminergic neurons that project to the striatum; their loss causes the motor deficits of Parkinson's disease.
Question 5: Long-term potentiation (LTP), a cellular model of memory formation, primarily involves which receptor?
- GABA-A receptor
- Muscarinic acetylcholine receptor
- NMDA glutamate receptor (Correct answer)
- D2 dopamine receptor
Correct answer: NMDA glutamate receptor
NMDA receptors act as coincidence detectors; their activation during LTP allows calcium influx that strengthens synaptic connections.
Question 6: The HPA axis stress response involves which sequence of hormone release?
- Cortisol → ACTH → CRH
- CRH → ACTH → Cortisol (Correct answer)
- ACTH → CRH → Cortisol
- Cortisol → CRH → ACTH
Correct answer: CRH → ACTH → Cortisol
The hypothalamus releases CRH, which triggers ACTH release from the pituitary, which then stimulates cortisol release from the adrenal cortex.
Question 7: Which method allows researchers to establish causal relationships between specific brain regions and behavior by temporarily disrupting neural activity?
- Functional MRI (fMRI)
- Electroencephalography (EEG)
- Transcranial Magnetic Stimulation (TMS) (Correct answer)
- Positron Emission Tomography (PET)
Correct answer: Transcranial Magnetic Stimulation (TMS)
TMS uses magnetic pulses to temporarily disrupt cortical activity, creating virtual lesions that allow causal inference about brain-behavior relationships.
BAPSY Biological Bases of Behavior 5
Which neurotransmitter is released at the neuromuscular junction to trigger muscle contraction?