Auditory responses from the frontal cortex in the mustached bat, Pteronotus parnellii

Response properties of neurons in an auditory field in the frontal cortex o f the mustached bat, Pteronotus parnellii, have not been studied before. We recorded neural responses to constant frequency (CF) stimuli from the fron tal auditory field in awake animals. The majority (75%) of neurons in this area responded well and often exhibited low thresholds to CF stimuli. Most CF-responsive neurons exhibited sharp tuning with values of > 180 for Q(10 db), a quality factor expressing the sharpness of tuning at 10 dB above thr eshold. Neurons at 13 recording sites exhibited combination sensitivity in that their responses were facilitated by presenting combinations of either CF1/CF2 and/or CF1/CF3 components of the mustached bat's echolocation signa l. Unlike the typical on-responses to a 30 ms tone, observed in the mustach ed bat's auditory cortex and at subcortical levels, many frontal auditory n eurons exhibited loosely rime locked firing patterns that lasted for > 100 ms. NeuroReport 11:367-372 (C) 2000 Lippincott Williams & Wilkins.