HMB200H1 Study Guide - Midterm Guide: Saccade, Deep Brain Stimulation, Circadian Rhythm
26 Feb 2013
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Document Summary
The cause of narcolepsy/cataplexy in humans appears to be due to the gradual loss of orexin/hypocretin neurons. These neurons are located in the lateral hypothalamus. Circadian rhythms in mammals are controlled by a negative feedback loop in which two proteins, per and cry combine (dimerize) to inhibit the gene transcription factors clock and cycle. Amphetamine acts on dopamine neurons in two ways: block dopamine transporters in the nucleus accumbens causing less reuptake, and stimulating dopamine release at the vta. Mauthner (m) cells are found in the medulla of fish and tadpoles and serve to evoke a fast escape response (c reflex). The rubrospinal tracts begins in the red nucleus then descends to the spinal cord in the lateral column. Inputs to the red nucleus come mainly from the cerebellum and motor cortex. 3 ways of treating parkinson"s disease: ingesting the precursor l-dopa, transplanting dopamine neurons, and deep brain stimulation.
