Localization of 5-HT1A and 5-HT2A positive cells in the brainstems of control age-matched and Alzheimer individuals.
Serotonin receptor 1A and 2A positive cells in postmortem brainstems were demonstrated via immunohistochemistry in eight control age-matched elderly individuals and eight Alzheimer patients. The 5-HT1A positive cells were found in substantia nigra, pontile nucleus, and vagal as well as dorsal raphe nucleus, while 5-HT2A receptor positive cells were found in motor, sensory and spinal trigeminal nuclei, pontile nucleus, substantia nigra, and nucleus solitarius. A comparison in density of positive cells per unit area was made between control age-matched and Alzheimer individuals. Statistically significant differences (p ≤ 0.01) in density were observed in 5-HT1A cells in pontile, dorsal raphe, and vagal nuclei between control age-matched and Alzheimer, and in 5-HT2A positive cells in the sensory trigeminal nucleus, between control and Alzheimer. This de novo study indicated the presence of 5-HT1A and 5-HT2A receptor positive cells in the above nuclei of human brainstem and revealed differences in density between control age-matched and Alzheimer, indicating possible functional derangements in Alzheimer patients in these areas. In addition, colocalization studies indicated that 5-HT1A receptors were in cholinergic cells and gamma-aminobutyric acid positive fibers were linked to 5-HT2A receptor positive cells. It is hoped that understanding these two important 5-HT receptors and their localization might lead to advances in future therapeutic development.
Yeung
L Y
LY
School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong S.A.R., China.
Kung
H F
HF
Yew
David T
DT
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000378:metabolism*; D015415:Biomarkers / Q000378:metabolism; D001933:Brain Stem / Q000378:metabolism*; D002102:Cadaver; D016022:Case-Control Studies; D006801:Humans; D007150:Immunohistochemistry; D008125:Locus Coeruleus / Q000378:metabolism; D008875:Middle Aged; D011149:Pons / Q000378:metabolism; D011903:Raphe Nuclei / Q000378:metabolism; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D044402:Receptor, Serotonin, 5-HT2A / Q000378:metabolism*; D017552:Solitary Nucleus / Q000378:metabolism; D013378:Substantia Nigra / Q000378:metabolism
D015415:Biomarkers; D044402:Receptor, Serotonin, 5-HT2A; D044282:Receptor, Serotonin, 5-HT1A