title: Feed-forward excitation of striatal neuron activity by frontal cortical activation of nitric oxide signaling in vivo.
abstract: The gaseous neurotransmitter nitric oxide plays an important role in the modulation of corticostriatal synaptic transmission. This study examined the impact of frontal cortex stimulation on striatal nitric oxide efflux and neuron activity in urethane-anesthetized rats using amperometric microsensor and single-unit extracellular recordings, respectively. Systemic administration of the neuronal nitric oxide synthase inhibitor 7-nitroindazole decreased spontaneous spike activity without affecting activity evoked by single-pulse stimulation of the ipsilateral cortex. Train (30 Hz) stimulation of the contralateral frontal cortex transiently increased nitric oxide efflux in a robust and reproducible manner. Evoked nitric oxide efflux was attenuated by systemic administration of 7-nitroindazole and the non-selective nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester. Train stimulation of the contralateral cortex, in a manner identical to that used to evoke nitric oxide efflux, had variable effects on spike activity assessed during the train stimulation trial, but induced a short-term depression of cortically evoked activity in the first post-train stimulation trial. Interestingly, 7-nitroindazole potently decreased cortically evoked activity recorded during the train stimulation trial. Moreover, the short-term depression of spike activity induced by train stimulation was enhanced following pretreatment with 7-nitroindazole and attenuated after systemic administration of the dopamine D2 receptor antagonist eticlopride. These results demonstrate that robust activation of frontal cortical afferents in the intact animal activates a powerful nitric oxide-mediated feed-forward excitation which partially offsets concurrent D2 receptor-mediated short-term inhibitory influences on striatal neuron activity. Thus, nitric oxide signaling is likely to play an important role in the integration of corticostriatal sensorimotor information in striatal networks.
authors: The Chicago Medical School at Rosalind Franklin University of Medicine and Science, Department of Neuroscience, 3333 Green Bay Road, North Chicago, IL 60064, USA.
authors: Janie M
authors: JM
authors: Ondracek
authors: Alexander
authors: A
authors: Dec
authors: Kristina E
authors: KE
authors: Hoque
authors: Sean Austin O
authors: SA
authors: Lim
authors: Golta
authors: G
authors: Rasouli
authors: Raksha P
authors: RP
authors: Indorkar
authors: John
authors: J
authors: Linardakis
authors: Brian
authors: B
authors: Klika
authors: Sawrav Josh
authors: SJ
authors: Mukherji
authors: Migena
authors: M
authors: Burnazi
authors: Sarah
authors: S
authors: Threlfell
authors: Stephen
authors: S
authors: Sammut
authors: Anthony R
authors: AR
authors: West
mesh_terms: D000818:Animals; D002540:Cerebral Cortex / Q000502:physiology*; D003342:Corpus Striatum / Q000502:physiology*; D004558:Electric Stimulation / Q000379:methods; D025461:Feedback, Physiological / Q000502:physiology*; D008297:Male; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D009569:Nitric Oxide