Serotonin Receptors and Transport

1328 Words3 Pages

Serotonin Receptors and Transport

Being that Fluoxetine (commercial name Prozac) basically

functions as a selective reuptake inhibitor for the

neurotransmitter serotonin, some discussion of this

transmitter is needed before its reuptake inhibition can be

addressed. Serotonin (5 hydroxytrytophan or 5HT, for short)

is synthesized from the precursor amino acid tryptophan

through the enzyme action of tryptophan hydroxylase (Abelson

& Andrews,1997,p.794). This synthesis process occurs in the

terminal boutons and the serotonin is contained in vesicles

awaiting release when an action potential opens the calcium

gates in the presynaptic terminal. Calcium flowing through

the gate adheres to the vesicle membrane and to the terminal

membrane causing the vesicle to rupture and release the

transmitter across the synaptic gap (Kalat,2004,p.61).

Serotonin has multiple receptor types and subtypes that

are linked to many diverse neurological functions. Beginning

in the 1970’s, radioligand techniques identified two broad

categories of receptors, namely types 5-HT1 and 5-HT2,

however, research has since identified another twelve types

and associated subtypes bringing the current total to

fourteen: 5HT1a,b,d,e,f, 5HT2a,b,c 5HT3, 5HT4, 5HT5a,b

5HT6, and 5HT7 (numbered suffixes represent types, lettered

suffixes are subtypes). These serotonin receptor types vary

by location within the brain, e.g., the highest density of

5HT1A receptors a found in the hippocampus and dorsal raphe

nucleus, whereas the highest concentration of 5-HT2 sites are

found in the medial prefrontal cortex (Abelson et al.

1997,p.794).

Once released into the synaptic gap, serotonin is not

broken down by...

... middle of paper ...

...

membrane (Williams et al,1998,p.3291). The exact mechanism

for the inhibition is not, as yet, fully understood, however,

a more complete chemical analysis of the likely processes is

provided in the preceding section entitled “Specific Chemical

Mechanisms.”

References

Abelson, J., & Andrews, P.(Eds.)(1997). Encyclopedia of Human

Biology. San Diego, CA: Academy Press.

Adelman, G. (Ed.)(1987). Encyclopedia of Neuroscience

(Vol.2). Boston: Birkhauser.

Kalat, J. W. (2004). Biological Psychology (8th ed.).

Belmont, CA: Thompson-Wadsworth.

Siegel, G.J., Agranoff, B.W., Albers, R.W., & Molinoff, P.B.

(1994). Basic neurochemistry (5th ed.). New York: Raven

Press.

Shepherd, G.M. (1994). Neurobiology (3rd ed.). London:

Oxford University Press.

Williams, S., & Mauro, S. (1998). European journal of

neuroscience, 10(10),3288-3295.

More about Serotonin Receptors and Transport

Open Document