Brain Bee - Study Guide

: Tight junctions between endothelial cells, supported by astrocyte end-feet. Circumventricular organs (area postrema, OVLT, etc.) lack BBB — they sample blood for toxins (vomiting center) or osmolality. Final Exam Question (Self-Test) A 65-year-old man has difficulty initiating movement, a resting "pill-rolling" tremor, and a shuffling gait. He is treated with L-DOPA. Which specific neuron population is degenerating, and what neurotransmitter do they normally release? Answer: Dopaminergic neurons in the substantia nigra pars compacta; neurotransmitter = dopamine. End of Deep Story. Use this narrative to anchor facts: imagine yourself as Pyra the pyramidal neuron, lifting the cup, and all the molecules and disorders that could help or hinder you. Good luck at the Brain Bee! 🧠🐝

AMPA receptors open. The LMN depolarizes enough to kick out the magnesium block from NMDA receptors. Now calcium enters the LMN — a key step for , the cellular basis of motor learning.

At the NMJ, the enzyme — sitting on the basal lamina — rapidly cleaves ACh into acetate and choline. Choline is taken back up into the LMN via the choline transporter (CHT1) , then reused. brain bee study guide

On the other side is your target: a in the ventral horn of the spinal cord, at the level of C5-C6 (imagine reaching for a cup). This LMN has ionotropic glutamate receptors — specifically, AMPA receptors (fast, Na+/K+) and NMDA receptors (slower, Ca2+ permeable, blocked by Mg2+ at rest).

You are about to initiate movement. The EPSP travels down your dendrites, summing at the axon hillock — your decision zone. Here, voltage-gated sodium channels wait. The membrane potential crosses threshold (-55 mV from resting -70 mV). Bang. : Tight junctions between endothelial cells, supported by

At the synapse onto the LMN, in the cleft take up excess glutamate via EAAT2 transporters , converting it to glutamine (via glutamine synthetase), sending it back to you to recycle.

Your biceps contracts. The cup lifts. But movement must be smooth and precise. You can't just blast away. He is treated with L-DOPA

The muscle fiber fires an action potential. on the T-tubule sense the voltage change and mechanically open ryanodine receptors (RyRs) on the sarcoplasmic reticulum. Calcium floods the cytosol.