Ssris alleviate symptoms of depression by increasing the a. frequency at which serotonin is released from synaptic vesicles b. number of serotonin receptors at the synapse c. level of serotonin at the synapse d. synthesis of serotonin

Ssris alleviate symptoms of depression by increasing the level of serotonin at the synapse .

Option C

Explanation:

Ssris (Selective serotonin re-uptake inhibitor) is a drug that is been prescribed to the people with depression and anxiety disorders.  In the brain the information and messages are passed from one nerve cell to the other.  

People with disorders find difficulty in transmitting the information. Hence a drug like SSRI's are prescribed to increase the level of serotonin at the synapse as the nerve cell passes the information through synapse the small gap between the cells.

b.have there own function.

answer; both surfaces of the membrane are nonpermeable