Neural Mechanism Of Parkinsonism

The basal ganglia can be viewed as a modulatory side loop that regulates the flow of information from the cerebral cortex to the motor neurons of the spinal cord (Figure 20-5). The net effect of stimulation of the direct pathway at the level of the striatum is to increase the excitatory outflow from the thalamus to the cortex; the net effect of stimulating the indirect pathway at the level of

D1 Receptor Family

D2 Receptor Family -N

t cyclic AMP t PIP2 hydrolysis ■ Ca2+ mobilization • PKC activation

4 cyclic AMP t K+ currents

4 voltage-gated Ca2+ currents

di

d5

• striatum

• hippocampus

• neocortex

• hypothalamus

d2

d3

d4

•striatum

• olf. tubercle

• frontal cortex

• SNpc

• n. accumbens

•medulla

• pituitary

• hypothalamus

• midbrain

FIGURE 20-4 Distribution and characteristics of dopamine receptors in the central nervous system. SNpc, sub-stantia nigra pars compacta.

Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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