Sensory-interference in rat primary somatosensory cortical neurons.
To study sensory interaction in the primary somatosensory cortex (SI), we registered 221 neurons in the SI of pentobarbital-anaesthetized Wistar rats. Tactile stimulation was applied in the receptive field of the SI neuron with an electronically controlled probe (20 ms duration). Tactile stimulation elicited 2.33 +/- 0.13 spikes per stimulus in SI neurons. Simultaneous application of paintbrush tickles of the contralateral limb usually decreased tactile responses (1.59 +/- 0.11 spikes per stimulus). This effect was considered a 'sensory-interference'. Light flashes applied at random did not modify tactile response. Applying atropine (1 mm), a muscarinic receptor antagonist, and bicuculline (1 mm), a GABAA receptor antagonist, to the SI cortex blocked the sensory-interference effect, while application of mecamylamine (10 mm), a nicotinic cholinergic receptor antagonist, did not affect sensory-interference. Results reveal sensory interactions in SI cortex that control tactile responses, and suggest the participation of the basal forebrain in the sensory-interference effect.
Alenda
Andrea
A
Departamento de Morfología, Facultad de Medicina, Universidad Autónoma de Madrid, Arzobispo Morcillo 4., 28029 Madrid, Spain.
Nuñez
Angel
A
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001640:Bicuculline / Q000494:pharmacology; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D005121:Extremities / Q000294:innervation / Q000502:physiology; D007839:Functional Laterality / Q000502:physiology; D018756:GABA Antagonists / Q000494:pharmacology; D008464:Mecamylamine / Q000494:pharmacology; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009433:Neural Inhibition / Q000502:physiology; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D018733:Nicotinic Antagonists / Q000494:pharmacology; D010812:Physical Stimulation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D013003:Somatosensory Cortex / Q000166:cytology* / Q000187:drug effects; D013997:Time Factors; D014110:Touch / Q000502:physiology*
D018756:GABA Antagonists; D018727:Muscarinic Antagonists; D018733:Nicotinic Antagonists; D008464:Mecamylamine; D001285:Atropine; D001640:Bicuculline