TY - JOUR
T1 - Increased nitric oxide synthase activity in a model of serotonin depletion
AU - Tagliaferro, Patricia
AU - Ramos, Alberto J.
AU - López-Costa, Juan José
AU - López, Ester M.
AU - Saavedra, Jorge Pecci
AU - Brusco, Alicia
PY - 2001/1/15
Y1 - 2001/1/15
N2 - Serotonin (5HT) containing cell bodies are localized in mesencephalic and rhombencephalic raphe nuclei. It has been proposed that 5HT could be involved in neuronal development and plasticity. In the central nervous system, nitric oxide (NO) has been postulated as a neurotransmitter and neuromodulator, and has been implicated in neurotoxicity as well as in neuroprotection. Using the nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) technique, NO synthesizing neurons were described in raphe nuclei. By immunohistochemistry, nitric oxide synthase (NOS) was found colocalized with 5HT in some dorsal raphe nucleus (DRN) neurons. In a model of inhibition of 5HT synthesis produced by daily administration of parachlorophenilalanine during 14 days, we have studied the relationship between 5HT and NO systems after 5HT depletion by histochemical and immunocytochemical methods. After the treatment, we observed an important reduction of 5HT immunostaining in the DRN and enhanced NOS activity demonstrated by NADPH-d technique, especially in the dorsomedial and ventromedial subgroups. In spite of the increased NOS activity, we could not observe significant changes in the NOS-immunoreactivity in the DRN after 5HT depletion. These results could indicate that 5HT depletion is concomitant with changes in NOS activity without affecting NOS expression in the DRN.
AB - Serotonin (5HT) containing cell bodies are localized in mesencephalic and rhombencephalic raphe nuclei. It has been proposed that 5HT could be involved in neuronal development and plasticity. In the central nervous system, nitric oxide (NO) has been postulated as a neurotransmitter and neuromodulator, and has been implicated in neurotoxicity as well as in neuroprotection. Using the nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) technique, NO synthesizing neurons were described in raphe nuclei. By immunohistochemistry, nitric oxide synthase (NOS) was found colocalized with 5HT in some dorsal raphe nucleus (DRN) neurons. In a model of inhibition of 5HT synthesis produced by daily administration of parachlorophenilalanine during 14 days, we have studied the relationship between 5HT and NO systems after 5HT depletion by histochemical and immunocytochemical methods. After the treatment, we observed an important reduction of 5HT immunostaining in the DRN and enhanced NOS activity demonstrated by NADPH-d technique, especially in the dorsomedial and ventromedial subgroups. In spite of the increased NOS activity, we could not observe significant changes in the NOS-immunoreactivity in the DRN after 5HT depletion. These results could indicate that 5HT depletion is concomitant with changes in NOS activity without affecting NOS expression in the DRN.
KW - Central nervous system
KW - Immunocytochemistry
KW - Nitric oxide
KW - Serotonin
UR - http://www.scopus.com/inward/record.url?scp=0035862541&partnerID=8YFLogxK
U2 - 10.1016/S0361-9230(00)00450-0
DO - 10.1016/S0361-9230(00)00450-0
M3 - Article
C2 - 11275409
AN - SCOPUS:0035862541
SN - 0361-9230
VL - 54
SP - 199
EP - 205
JO - Brain Research Bulletin
JF - Brain Research Bulletin
IS - 2
ER -