[Effects of sodium salicylate on the expressions of gamma-aminobutyricacid and glutamate and auditory response properties of the inferior colliculus neurons].
The effects of sodium salicylate (NaSA) on the expressions of gamma-aminobutyricacid (GABA) and glutamate (Glu), and auditory response properties of the inferior colliculus neurons in mice were studied. Thirty-six Kunming mice were divided into three groups: control group (saline injection); NaSA group (NaSA 450 mg/kg, i.p., each day for 15 d); NaSA + lidocaine group (NaSA 450 mg/kg + lidocaine 10 mg/kg, i.p., each day for 15 d). The expressions of GABA and Glu were examined with immunohistochemical method. The intensity-rate function, intensity-latency function and frequency-tuning curve were determined with extracellular electrophysiological recording. Results are as follows: (1) The expression of GABA in the NaSA and NaSA + lidocaine groups decreased remarkably compared with that in the control group; there was no noticeable difference between the NaSA and NaSA + lidocaine groups. The expression of Glu in the NaSA group increased significantly compared with that in the control and NaSA + lidocaine groups. No difference in the expression of Glu was found between the control and NaSA + lidocaine groups. (2) In NaSA group, the intensity-rate function displayed a non-monotonic pattern, rising at low intensity and descending at high intensity; the tip of frequency-tuning curves became broad after administration of NaSA. (3) The changes in intensity-rate function and intensity-latency function were not evident and the tips of the frequency-tuning curves sharpened in the NaSA + lidocaine group. These results suggest that administration of NaSA increases the expression of Glu-positive neurons and reduces that of GABA-positive neurons in the inferior colliculus. NaSA changes the auditory response properties of the inferior colliculus and lidocaine can reverse these changes.
Yin
Shi-Hua
SH
Department of Otorhinolaryngology, First Clinical College, Guangxi University of Medical Sciences, Nanning 530021, China. shihuayin@yahoo.com.cn
Tang
An-Zhou
AZ
Xing
Xiao-Ling
XL
Tan
Song-Hua
SH
Xie
Li-Hong
LH
D000161:Acoustic Stimulation; D000818:Animals; D005260:Female; D005971:Glutamates / Q000032:analysis*; D018698:Glutamic Acid / Q000032:analysis; D007150:Immunohistochemistry; D007245:Inferior Colliculi / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D011930:Reaction Time / Q000187:drug effects; D012980:Sodium Salicylate / Q000494:pharmacology*; D005680:gamma-Aminobutyric Acid / Q000032:analysis*
D005971:Glutamates; D018698:Glutamic Acid; D005680:gamma-Aminobutyric Acid; D012980:Sodium Salicylate