eCite Digital Repository

Spontaneous and stimulus-evoked intrinsic optical signals in primary auditory cortex of the cat


Spitzer, MW and Calford, MB and Clarey, JC and Pettigrew, JD and Roe, AW, Spontaneous and stimulus-evoked intrinsic optical signals in primary auditory cortex of the cat, Journal of Neurophysiology, 85, (3) pp. 1283-1298. ISSN 0022-3077 (2001) [Refereed Article]

DOI: doi:10.1152/jn.2001.85.3.1283


Spontaneous and tone-evoked changes in light reflectance were recorded from primary auditory cortex (AI) of anesthetized cats (barbiturate induction, ketamine maintenance). Spontaneous 0.1-Hz oscillations of reflectance of 540- and 690-nm light were recorded in quiet. Stimulation with tone pips evoked localized reflectance decreases at 540 nm in 3/10 cats. The distribution of patches "activated" by tones of different frequencies reflected the known tonotopic organization of auditory cortex. Stimulus-evoked reflectance changes at 690 nm were observed in 9/10 cats but lacked stimulus-dependent topography. In two experiments, stimulus-evoked optical signals at 540 nm were compared with multiunit responses to the same stimuli recorded at multiple sites. A significant correlation (P < 0.05) between magnitude of reflectance decrease and multiunit response strength was evident in only one of five stimulus conditions in each experiment. There was no significant correlation when data were pooled across all stimulus conditions in either experiment. In one experiment, the spatial distribution of activated patches, evident in records of spontaneous activity at 540 nm, was similar to that of patches activated by tonal stimuli. These results suggest that local cerebral blood volume changes reflect the gross tonotopic organization of AI but are not restricted to the sites of spiking neurons.

Item Details

Item Type:Refereed Article
Keywords:barbituric acid derivative; ketamine; adolescent; animal experiment; article; auditory cortex; auditory stimulation; cat; evoked auditory response; nerve conduction; nonhuman; oscillation; priority journal; signal transduction; Cats
Research Division:Biomedical and Clinical Sciences
Research Group:Neurosciences
Research Field:Neurology and neuromuscular diseases
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Calford, MB (Professor Mike Calford)
ID Code:91292
Year Published:2001
Web of Science® Times Cited:36
Deposited By:Research Division
Deposited On:2014-05-13
Last Modified:2014-05-13

Repository Staff Only: item control page