sfn2001

Yan J, Price DL, Koliatsos VE (2001) Nestin expression in neurons of the medial septum/diagonal band in the adult rat. Neuroscience 2001 Abstracts 25.9. Society for Neuroscience, San Diego, CA.

Summary: Nestin is a marker for neuronal precursor cells in normal animals. In adult animals, nestin (+) cells are limited to the ventricular wall, hippocampus and the rostral migratory stream, where neurogenesis is known to persist throughout life. We are now reporting the existence of nestin (+) cells in the medial septum/diagonal band area based on immunocytochemical staining with different nestin antibodies. Many of these cells colocalize ChAT and nestin. In addition, some nestin (+) cells can be traced with the carbocyanin dye SP-DiI injected into the lateral ventricle to label cell lineages originating in the ependymal layer. Medial septal/diagonal band lesions by complete fimbria-fornix transections or 192-IgG-saporin conjugate injections into the ventricle cause an increase in BrdU (+) and nestin (+) cells in medial septum/diagonal band especially in anterior planes. We are currently double labeling the sections with BrdU and nestin or TUJ1. Our working hypothesis is that there may be ongoing neurogenesis in the medial septum/diagonal band in the adult brain, especially after injury or under pathological conditions and this may have implications for pathogenesis and treatment of Alzheimer’s disease.

Related Products: 192-IgG-SAP (Cat. #IT-01)

Gu JG, Nakatsuka T, Tanaka E, Takeda D, Jennifer LX (2001) Capsaicin-sensitive inhibitory pathway in rat spinal cord dorsal horn. Neuroscience 2001 Abstracts 158.13. Society for Neuroscience, San Diego, CA.

Summary: The inhibitory system in the spinal cord plays an important role in regulating nociceptive sensory inputs. Here we examined inhibitory synaptic activity in lamina V neurons of the spinal dorsal horn following the activation of capsaicin VR1 receptors. Experiments were performed with spinal cord slice preparations and inhibitory postsynaptic currents (IPSCs) were recorded using patch-clamp technique. Bath application of capsaicin (2 μM) increased the amplitude and frequency of GABAergic and glycinergic spontaneous IPSCs in the majority of lamina V neurons tested. The effects of capsaicin were completely antagonized by capsazepine (10 μM), and were also blocked in the presence of tetrodotoxin (0.5 μM). However, when CNQX (20 μM) and APV (100 μM) were used to block glutamatergic synaptic transmission, the effects of capsaicin were not abolished. Furthermore, after the injection of IB4-saporin into sciatic nerve to remove IB4-positive C-primary afferent terminals, capsaicin still increased sIPSC frequency in the presence of CNQX and APV. These results suggest that inhibitory pathway could be recruited in the absence of glutamatergic inputs from primary afferents. The release of neuropeptides from capsaicin-sensitive C-primary afferents may activate GABAergic and glycinergic interneurons in superficial laminae, and the inhibitory activity may be further forwarded to lamina V neurons. The capsaicin-sensitive inhibitory pathway may play an important role in the control of nociceptive transmission in the spinal cord.

Related Products: IB4-SAP (Cat. #IT-10)