HOMEWORK 4

Which hormone's release is primarily influenced by the SCN and is crucial for sleep regulation?

Melatonin 

How does the retinohypothalamic pathway contribute to circadian rhythm regulation?

It sends light information directly to the SCN.

Why does caffeine help individuals stay awake?

It blocks adenosine receptors

What is a key feature of the molecular clock mechanism in SCN cells?

Per and Cry proteins inhibit Clock and Bmal1 transcription.

Why does melatonin secretion decrease in response to light?

The SCN inhibits the pineal gland when activated by light.

What happens to circadian rhythms when an SCN transplant is performed using tissue from a tau mutant hamster?

The recipient's rhythms become shorter

According to Schachter’s cognitive attribution model, what influences the emotions we experience?

• An interaction between physiological arousal and environmental context 

Which brain structure is associated with fear?

amygdala

How do positive expectations influence pain perception?

• They reduce perceived pain through placebo effects

Which brain structure is associated with ‘liking’ in reward processing?

• Ventral pallidum 

Muscimol inactivation of the  _____ showed that it is critical for fear extinction

• medial prefrontal cortex

Given the data gathered from individuals with Urbach-Wiethe disease, you would likely assume it affects the:

amygdala

Which symptom is classified as a positive symptom in schizophrenia?

• Hallucinations 

Which of the following neurological abnormalities is associated with schizophrenia?

• Enlarged cerebral ventricles 

Positive symptoms of schizophrenia are associated with ______ ______

increased; dopamine

PTSD can be characterized as a form of extreme fear conditioning coupled with failure to extinguish. Given what you know about extinction in fear learning, which brain structure would you expect to find decreased activity in with a PTSD patient?

medial prefrontal cortex

Think back to what you've learned about drug mechanisms of action in this course. Given what you know about the neurobiology of positive symptoms in schizophrenia, which of the following drugs would be most likely to produce a similar syndrome following chronic use: 

methamphetamine

How does NMDA receptor activation contribute to LTP?

•  It allows calcium ions to enter the postsynaptic cell 

Which of the following best explains the role of retrograde messengers in LTP?

• They signal the presynaptic neuron to release more glutamate  

In the context of LTP, what happens when the postsynaptic membrane reaches a sufficient voltage?

• Magnesium ions are expelled from NMDA receptors  

How does low-frequency stimulation influence synaptic plasticity?

It leads to long-term depression (LTD)

LTP requires _____ ; LTD requires ______

Protein kinases; protein phosphatases

Blocking AMPA receptors would:

prevent LTP

You place a rat in a box and play a white noise sound at it, then shock it. Over time, the rat begins to freeze when it hears the sound. The rat's freezing behavior when hearing the sound is considered the:

conditioned response

What is the primary input zone of the trisynaptic circuit of the hippocampus?

• Entorhinal Cortex 

Which of the following is an example of procedural memory?

• Learning to ride a bike 

HM's performance in the mirror-tracing task suggest that procedural memory is: 

• Not hippocampal-dependent 

Episodic memories differ from semantic memories in that:

• Increasing numbers of similar events weaken episodic memories

Which of the following types of memory would be hippocampal-dependent?

• Directions from your apartment to the nearest bar 

Which area of the brain is an active site of neurogenesis?

dentate gyrus

Cells that build a pattern and fire the represent specific points in space as you learn to map an area

place cells

Guides attentional eye movements 

• Superior colliculus 

As the odds of receiving a reward go up, PFC dopamine goes ___; D1 agonist/activation ___ impulsive/risky choice 

down; increases