Preferential modulation of the lateral habenula activity by serotonin-2A rather than -2C receptors: Electrophysiological and neuroanatomical evidence.
CNS Neurosci Ther
; 24(8): 721-733, 2018 08.
Article
em En
| MEDLINE
| ID: mdl-29479825
ABSTRACT
AIMS:
Serotonergic (5-HT) modulation of the lateral habenula (LHb) activity is central in normal and pathologic conditions such as mood disorders. Among the multiple 5-HT receptors (5-HTRs) involved, the 5-HT2C R seems to play a pivotal role. Yet, the role of 5-HT2A Rs in the control of the LHb neuronal activity is completely unknown.METHODS:
Single-cell extracellular recording of the LHb neurons was used in rats to study the effect of the general activation and blockade of the 5-HT2C R and 5-HT2A R with Ro 60-0175 and SB242084, TCB-2 and MDL11939, respectively. The expression of both receptors in the LHb was confirmed using immunohistochemistry.RESULTS:
Cumulative doses (5-640 µg/kg, iv) of Ro 60-0175 and TCB-2 affected the activity of 34% and 63% of the LHb recorded neurons, respectively. LHb neurons were either inhibited at low doses or excited at higher doses of the 5-HT2A/C R agonists. SB242084 or MDL11939 (both at 200 µg/kg, iv) did not modify neuronal firing when injected alone, but reverted the bidirectional effects of Ro 60-0175 or TCB-2, respectively. 5-HT2C Rs and 5-HT2A Rs are expressed in less than the 20% of the LHb neurons, and they neither colocalize nor make heterodimers. Strikingly, only 5-HT2A Rs are expressed by the majority of LHb astrocyte cells.CONCLUSIONS:
Peripheral administration of 5-HT2A R agonist promotes a heterogeneous pattern of neuronal responses in the LHb, and these effects are more prominent than those induced by the 5-HT2C R activation.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Potenciais de Ação
/
Habenula
/
Receptor 5-HT2A de Serotonina
/
Receptor 5-HT2C de Serotonina
/
Neurônios
Limite:
Animals
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article