Autofluorescence spectrofluorometry of central nervous system (CNS) neuromediators.
OBJECTIVE
Changes in the neurotransmitter 5-hydroxytriptamine (5-HT) are related to psychiatric diseases such as depression and anxiety. In this study, 5-HT autofluorescence properties were investigated in solution and in biological tissues.


METHODS
Spectrofluorometric characterization was performed on ex vivo samples (tissue sections, homogenates) of the 5-HT-rich brain region hippocampus from rats untreated or treated to affect endogenous 5-HT levels; in vivo, with a 50 solidus in circle optic fiber probe positioned via stereotaxis.


RESULTS
5-HT exhibited minor excitation and emission bands at wavelengths longer than the well known excitation and emission bands in the UV region, 250-320 nm. Spectrofluorometric measurements under 366 nm excitation on homogenates supplied with 5-HT or belonging to treated rats revealed spectral alterations attributable to changes in the amount of 5-HT. Ex vivo and in vivo autofluorescence data were consistent with those obtained by conventional voltammetry.


CONCLUSIONS
Autofluorescence spectroscopy potential is confirmed as a suitable technique for the direct measurement of neurotransmitters.
Crespi
Francesco
F
Department of Biology, Psychiatry C.E.D.D., GlaxoSmithKline S.p.A., Verona, Italy.
Croce
Anna C
AC
Fiorani
Sabrina
S
Masala
Barbara
B
Heidbreder
Christian
C
Bottiroli
Giovanni
G
D000818:Animals; D006624:Hippocampus / Q000737:chemistry*; D066298:In Vitro Techniques; D008297:Male; D051381:Rats; D012701:Serotonin / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods
D012701:Serotonin