Question

All three diseases are associated with some type of progressive disorganization of movement, which may be a gradual loss of movement or gradual increase in overt movements. Some form of tremor can be seen during some stage of all three as well. Two diseases have distinct tremor patterns that are “hallmarks” of the conditions. Affected individuals have “gait” changes, once again being quite distinct for two of the diseases. Short-term and recent memory loss are typical of Parkinson’s and Alzheimer’s diseases and often eventually for Huntington’s disease. Other common signs and symptoms include various levels of disorientation, anxiety, depression, and ultimately other symptoms of dementia.    Dysphasia is eventually seen in all three, and dysarthria is common in at least two of them communication and cognitive skills gradually deteriorate in all three.

1] Which part of a neuron releases neurotransmitters? To where is the neurotransmitter released? Explain the process whereby neurotransmitters are released.

2] How do stimulatory and inhibitory neurotransmitters affect the membrane potential of the postsynaptic membrane? What ion channels are involved with each type of neurotransmitter?

3] Once a neurotransmitter is released, how is it stopped from continuously stimulating or inhibiting the postsynaptic membrane?

4] What is the general location and function of the basal nuclei?

5] What are 2 of the principal functions of EACH of the following neurotransmitters? A] Dopamine: B] GABA: C] Acetylcholine:

6] Consider the example of a “withdrawal reflex” pathway. Why is it necessary for coordinated motor activities to have both excitatory and inhibitory components?

7] Match the three diseases with the first prominent sign of each:

         Memory loss of recent events:                                                              

         Depression, often manic:                                                                      

         Muscle rigidity and slowing of overall movements:                                                  

Answer 1

Neurological disorders are diseases which affect brain ,central and autonomic nervous systems.There are many types of neurological disorders such as Alzheimer's, Epilepsy, Multiple sclerosis,parkinson's disease and migraines.

1) The neurotransmitters which are made in the cell body move across the synapsis to detect and bind the receptors.The presynaptic or axion terminal of a neuron which releases neurotransmitters into the synaptic cleft. The neurotransmitters are packed inside small vesicles. When this action invades the nerves, the calcium channel opens and calcium flows into the cell. It triggers the fusion of neurotransmitters.

2) The stimulatory and inhibitory neurotransmitters generate an action potential. These neurons release neurotransmitters at inhibitory synapsis leads to hyperpolarization of the presynaptic membrane and bind with receptors. It induces to change the permeability of membrane to particular ions.

Ionotropic receptors means ionscan pass through the receptors.It is also known as Ligand-gated ion channels which can be excited by neurotransmitters like glutamate and aspartate.These can be inhibited by GABA and glycine.

3)When the neurotransmitter is released it binds and activates a receptor in postsynaptic membrane. Its deactivation can affect it leads to destruction or return it into the terminal from which it came, where it can be processed .

4) The basal nuclei is located within the cerebral hemispheres which is interconnected with cerebral cortex, thalamus, brain stem and other areas of brain.

The basal nuclei performs 3 various types of functions. Input nuclei receives signals from brain and send signals from basal ganglia to thalamus with the help of output nuclei. The intrinsic nuclei helped to relay nerve signals and information between input nuclei and output nuclei. After the information has been processed the basal ganglia receives from thalamus and cerebral cortex.

5) Dopamine is a chemical messenger in the brain which performs the functions like motivation, movement ,sleep behavior and cognition.

GABA i sends chemical messenges through brain and nervous system. It helps in communication between brain cells.It also reduces activities of nerve cells.

Acetylecholine is also a neurotransmitter which helps muscles to contract, contols endocrine,regulate pain responses and perform sleep functions.