Restorative Neurology and Neuroscience - Volume 11, issue 1-2

Authors: Li, Ying J. | Hartman, Boyd K. | Faris, Patricia L. | Low, Walter C.

Article Type: Research Article

Abstract: The retrosplenial cortex (RSC) is a target of the forebrain cholinergic projecting system. It receives extensive cholinergic innervation from the medial septal nucleus and the diagonal band of Broca. These cholinergic afferents travel along the paths of cingulate bundle and fornix. In the present study we investigated the ability of cholinergic fetal septal grafts to reinnervate the deafferented RSC. Four groups of rats were used: (1) normal control rats (NC); (2) rats with bilateral transections of the cingulate bundle (CgX); (3) rats with simultaneous lesions of both the cingulate bundle and the fornix (FX), and (4) rats with intra-retrosplenial fetal …septal grafts and lesions in both cingulate bundle and the fornix (RSCsep-TPL). We found that lesions in the cingulate bundle alone produced a modest reduction of cholinergic innervation whereas lesions in both the fornix and cingulate bundle resulted in a complete loss of cholinergic inputs in this area, indicating that both the cingulate bundle and the fornix are involved in mediating cholinergic projections from the septal-diagonal area to the RSC. Transplantation of cholinergic fetal septal neurons into the RSC of animals with simultaneous lesions in both the fornix and cingulate bundle restored the cholinergic innervation pattern to that which is typical of the normal septo-retrosplenial inputs. These results provide the neuroanatomical basis for behavioral studies which have documented graft-mediated recovery of spatial memory function in rats with lesions of the cholinergic septo-retrosplenial pathways Show more

Keywords: Retrosplenial cortex, Cingulate bundle, Fornix, Cholinergenic projections, Lesions

DOI: 10.3233/RNN-1997-111211

Citation: Restorative Neurology and Neuroscience, vol. 11, no. 1-2, pp. 99-108, 1997

Authors: Angelov, Doychin N. | Neiss, Wolfram F. | Gunkel, Andreas | Streppel, Michael | Guntinas-Lichius, Orlando | Stennert, Eberhard

Article Type: Research Article

Abstract: Hypoglossal-facial anastomosis (HFA), used for the treatment of facial palsy, was performed in adult Wistar rats. For 7–224 days post operation (DPO), half of the animals were kept on standard laboratory food and half received food pellets containing 1000 ppm of the Ca2+ channel blocker nimodipine. The postoperative neurotization of facial muscles in these two groups was traced by comparing numbers of all retrogradely labeled neurons after injection of HRP into the whiskerpad muscles. In unoperated animals, injection of HRP labeled 1254 ± 54 neurons. Immediately after HFA, this number dropped to zero. The treatment with nimodipine yielded two …beneficial effects. (1) In the early phase of regeneration (until 28 DPO), it accelerated the sprouting of hypoglossal axons into the facial periphery; (2) In the final phase, it suppressed the axonal sprouting from both, hypoglossal and facial stumps. In this way nimodipine fully prevented the postoperative hyperinnervation, i.e. the projection of more hypoglossal plus facial motoneurons to the whiskerpad muscles than under normal conditions. Show more

Keywords: Rat, Facial nerve, Hypoglossal nerve, Nerve suture, Retrograde tracing, Nimodipine, Neuron number

DOI: 10.3233/RNN-1997-111212

Citation: Restorative Neurology and Neuroscience, vol. 11, no. 1-2, pp. 109-121, 1997