The smooth, co-ordinated
movement of the human body is accomplished by the concerted action of neurones
at multiple levels. The impulse for a movement begins in the cerebral cortex
and travels to the lower motor neuron, but not before the impulse has been
modulated through inputs at the level of striatum, Substantia Nigra and other
parts of the brain. The inputs can be either excitatory or inhibitory. The
objective is to achieve a smooth, graceful movement at the end.
The neuronal circuitry involves
a lot of complexities.
However, the final
simplification is-
In the striatum, dopaminergic
pathway have a net inhibitory action and the cholinergic pathway have a net
excitatory action.
In Parkinson’s disease, there is
degeneration of the dopaminergic pathway.
So, Parkinson’s disease is a
dopamine deficient state and therefore, treated with replacement of dopamine,
or by inhibiting metabolism of dopamine or by administering dopamine agonist.
Thank you sir , the concept and language is so clearly written
ReplyDeleteVery helpful.. Thank you sir.
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