Functional mapping of the rat brain during vocalizations: a 2-deoxyglucose study.
Autoradiographic [14C]2-deoxyglucose (2-DG) procedures were used to map the functional activity in the CNS during vocalizations elicited by electrical stimulation of the midbrain reticular formation (MRF) in behaving rats. Following injection of 2-DG, rats received MRF stimulation through stainless steel electrodes over 90 min. Yoked controls received 2-DG injection followed by playback of the recorded vocalizations. Relative differences in peak isotope uptake (gray/white matter ratios) in 22 structures related to vocalization were compared between the two groups. The major findings were localized to hypothalamus, midbrain and brainstem structures. Significant increases in 2-DG uptake were noted in the following structures in MRF stimulated rats: dorsolateral central gray (PAG), MRF, lateral hypothalamus (LH), ventromedial hypothalamus (VmH), paraventricular nucleus (PVN) and nucleus ambiguus (NA). Cortical structures were not activated during MRF stimulation. The PAG and NA are known to be important relays in the production of vocalizations. MRF stimulation, therefore, activates the motor output pathways for vocalization, but does not appear to activate cortical and limbic motivational centers.
Gonzalez-Lima
F
F
Department of Medical Anatomy, Texas A&M University, College Station.
Frysztak
R J
RJ
D000818:Animals; D001931:Brain Mapping; D003847:Deoxyglucose / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004734:Energy Metabolism; D019788:Fluorodeoxyglucose F18; D007031:Hypothalamus / Q000502:physiology*; D008297:Male; D008526:Medulla Oblongata / Q000502:physiology*; D010286:Paraventricular Hypothalamic Nucleus / Q000502:physiology*; D010487:Periaqueductal Gray / Q000502:physiology*; D051381:Rats / Q000033:anatomy & histology* / Q000502:physiology; D014828:Vocalization, Animal / Q000502:physiology*
D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose