John L. Beggs, PhD,
Division of Neuropathology
|Electron microscope image of nerve cells, the arrows indicate the synapse in a firing state.
The Electron Microscopy Laboratory's principal goal is to provide electron microscopy services to Barrow Neurological Institute investigators. During the past 40 years, the laboratory has collaborated on studies with several departments within the institute including Neuropathology, Neurology, Neurosurgery, and Neurobiology.
Currently, several studies are under way:
- 3-D reconstruction of lamina 1 spinothalamic terminals in the thalamus (Beggs, Craig)
- Fine structure of hypothalamic hamartomas (Coons, Beggs, Kerrigan)
- EM study of a subtype of Charcot-Marie-Tooth neuropathy (Sivakumara, Coons, Beggs)
- Fine structure of nemaline bodies in the muscle of mutant mice (Sivakumara, Coons, Beggs)
Clinical The Electron Microscopy Laboratory plays a key role in clinical research by providing diagnostic services for certain diseases of the central nervous system, peripheral nervous system, and muscle. A quantitative method for examining respiratory cilia has been developed.
The Electron Microscopy Laboratory provides images to support the teaching of residents and presentations to staff. Currently, an atlas of ultrastructural neuropathology is being prepared. The atlas will include valuable ultrastructural data dating to the inception of the Barrow Neurological Institute.
Major Research Accomplishments
The Electron Microscopy Laboratory has been provided data for the following published studies:
- Coverings of the nervous system (1)
- Viral and bacterial infections of the CNS (2, 5)
- Vasogenic edema following injury to the CNS (4, 6, 7, 10, 11)
- Laser and suture technique in nerve anastomosis (12, 13 15)
- Blood supply to normal peripheral nerves (21, 24)
- Innervations of the vasa nervorum in normal nerves (24, 27) in diabetic neuropathy (25, 26, 28) and vasculitic neuropathy (29)
- Fate of perineurial cell basement membrane in a human diabetic following isogenic pancreas transplant (19, 20)
- Capillaries in diabetic and nondiabetic skin (18, 23)
- Method for estimating unmyelinated nerve fiber density in peripheral nerve (30)
- Developed an EM method used to test the effects of Tolrestat on nerve fiber regeneration in diabetic neuropathy; the two-year drug study was funded by Wyeth-Ayers 3-D reconstruction of lamina 1 spinothalamic terminals in the thalamus (31)
- Nerve disease in five families(60 patients) with mutations in the glycyl-tRNA synthetase gene (Sivakumar K., et al. Brain 2005)