Parkinson's disease,characterized by tremors and rigidity of limbs,is caused by the degeneration of brain cells involved in movement control and the use of which neurotransmitter?

Axon terminal is indicated by which alphabet in the given figure?

Suppose the terminal ends of an axon are in contact with the dendrites of four adjacent neurons,the nerve impulse of the axon will

Which of the following statements are correct regarding electrical synapses?
$i.$ At electrical synapses,the membranes of pre- and post-synaptic neurons are in very close proximity.
$ii.$ Electrical current can flow directly from one neuron into the other across these synapses.
$iii.$ Impulse transmission across an electrical synapse is very similar to impulse conduction along a single axon.
$iv.$ Electrical synapses transmit signals using neurotransmitters like acetylcholine.
$v.$ Electrical synapse transmission is very fast.
$vi.$ Electrical synapses are rare in our system.

What is a synapse? How many types of synapses are found? Discuss the conduction of a nerve impulse through a synapse with a diagram.

$A$ : Transmission of the nerve impulse across a synapse is accomplished by neurotransmitters.
$R$ : Transmission across a synapse usually requires neurotransmitters because there is a small space,$i.e.$,synaptic cleft,that separates one neuron from another.