Lee R, Gallegos RA, Crawford EF, Wills DN, Zhukov VI, Huitron-Resendiz S, Criado JR, Henriksen SJ (2003) Ventral tegmental area lesions alter EEG power spectrum across the sleep/wake cycle. Neuroscience 2003 Abstracts 616.5. Society for Neuroscience, New Orleans, LA.
Summary: The ventral tegmental area (VTA) has long been implicated in reward and drug abuse. We previously demonstrated (Lee et al, J. Neurosci. 2001) a role for VTA GABAergic neurotransmission in REM sleep. In continuing studies the potential role of the VTA in modulating electroencephalogram (EEG) activation was explored by selectively lesioning mu-opioid receptor expressing cells, or NMDA-lesioning cells, in the VTA. Under sodium pentobarbital anesthesia rats received either (1) a sham operation (2) a saporin injection (3) an injection of a dermorphin-saporin (DERM-SAP) conjugate (Advanced Targeting Systems, San Diego, CA) (4) or a bilateral VTA injection of NMDA. All injections were delivered in a volume of 0.5 to 1.0 µL over 4 to 8 minutes. Animals were also implanted with electrodes for recording the EEG & EMG. The filtered EEG & EMG were recorded continuously for 24 hours beginning 21 days after surgery. Frequency analysis of the EEG in 15-sec epochs revealed differences in the distribution of relative power in the DERM-SAP or NMDA-lesioned animals, compared to controls. Higher frequency components (12-25 Hz) were reduced in DERM-SAP lesioned animals during waking and slow wave sleep. Histology demonstrated gliosis of GAD-stained neurons in the VTA 3 to 4 weeks after injection of DERM-SAP. These data suggest that long-projecting GABA neurons of the VTA have a desynchronizing influence on cortical EEG arousal mechanisms. This is supported by anatomical evidence of both direct and indirect non-thalamic GABAergic projections to widespread areas of cortex in the rodent. Supported by: DA08301 to SJH.
Related Products: Dermorphin-SAP / MOR-SAP (Cat. #IT-12)