PT  - JOURNAL ARTICLE
AU  - Thomas C. Pritchard
AU  - Erin M. Edwards
AU  - Carrie A. Smith
AU  - Kristen G. Hilgert
AU  - Andrew M. Gavlick
AU  - Thomas D. Maryniak
AU  - Gary J. Schwartz
AU  - Thomas R. Scott
TI  - Gustatory Neural Responses in the Medial Orbitofrontal Cortex of the Old World Monkey
AID  - 10.1523/JNEUROSCI.0430-05.2005
DP  - 2005 Jun 29
TA  - The Journal of Neuroscience
PG  - 6047--6056
VI  - 25
IP  - 26
4099  - http://www.jneurosci.org/content/25/26/6047.short
4100  - http://www.jneurosci.org/content/25/26/6047.full
SO  - J. Neurosci.2005 Jun 29; 25
AB  - The primary taste cortex has widespread and occasionally dense projections to the orbitofrontal cortex (OFC) in the macaque. Nonetheless, electrophysiological studies have revealed that only 2-8% of the cells in the OFC are activated by taste stimuli on the tongue. We describe an area centered in Brodmann's area 13m of the medial OFC (mOFC) where taste neurons are more concentrated. It consists of a 12 mm2 core, where gustatory neurons constituted 20% of the population, and a 1 mm perimeter in which 8% of the cells responded to taste. Data were collected from three awake cynomolgus monkeys (Macaca fascicularis) prepared for chronic recording. Single neurons were isolated with epoxylite-coated tungsten microelectrodes and tested for responsiveness to 1.0 m glucose, 0.3 m NaCl, 0.03 m HCl, and 0.001 m QHCl. These stimuli elicited responses that were 96% excitatory and ranged from 5.2 to 5.9 spikes/s. Cells were broadly tuned (H = 0.79), similar to those in the anterior insula (H = 0.70), and decidedly unlike the narrowly tuned taste neurons in the caudolateral OFC (clOFC; H = 0.39). Whereas 82% of the taste cells in the clOFC respond to glucose, in the mOFC, HCl-responsive (56%), glucose-responsive (50%), NaCl-responsive (43%), and QHCl-responsive (40%) cells were almost evenly represented. The mOFC taste area appears to comprise a major gustatory relay that lies anatomically and functionally between the anterior insula and the clOFC.