Gain modulation by nicotine in macaque v1.
Neuron
; 56(4): 701-13, 2007 Nov 21.
Article
en En
| MEDLINE
| ID: mdl-18031686
ABSTRACT
Acetylcholine is a ubiquitous cortical neuromodulator implicated in cognition. In order to understand the potential for acetylcholine to play a role in visual attention, we studied nicotinic acetylcholine receptor (nAChR) localization and function in area V1 of the macaque. We found nAChRs presynaptically at thalamic synapses onto excitatory, but not inhibitory, neurons in the primary thalamorecipient layer 4c. Furthermore, consistent with the release enhancement suggested by this localization, we discovered that nicotine increases responsiveness and lowers contrast threshold in layer 4c neurons. We also found that nAChRs are expressed by GABAergic interneurons in V1 but rarely by pyramidal neurons, and that nicotine suppresses visual responses outside layer 4c. All sensory systems incorporate gain control mechanisms, or processes which dynamically alter input/output relationships. We demonstrate that at the site of thalamic input to visual cortex, the effect of this nAChR-mediated gain is an enhancement of the detection of visual stimuli.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Corteza Visual
/
Vías Visuales
/
Percepción Visual
/
Receptores Nicotínicos
/
Neuronas
/
Nicotina
Idioma:
En
Revista:
Neuron
Asunto de la revista:
NEUROLOGIA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Estados Unidos