摘要:

AbstractThere is one particularly large axon in the medial bundle of the nerve cord of the leech. It extends along the entire length of the cord and is connected to a single cell body in each ganglion. The cell bodies in adjacent ganglia are tightly electrically coupled, and dye injected into one cell body can diffuse along the axon and into the cell body of the next ganglion. If the nerve cord is cut between two ganglia, neither end of the axon degenerates. Repair of the axon appears to occur by end‐to‐end fus

ISSN:0092-7317    

DOI:10.1002/cne.901590102

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractRetinogeniculate pathways have been studied by fiber degeneration and autoradiographic methods in rabbits that are homozygous for alleles of the albino series of genes. It has been found that albino and Himalayan rabbits, which both lack all melanin pigment in the eye, have a similar abnormality of the retinogeniculate pathway. The number of ipsilateral optic fibers going to the lateral geniculate nucleus is reduced in these rabbits, the ipsilateral projection forms a discontinuous terminal zone instead of the normal continuous zone, and some of the ipsilateral axons terminate in an inappropriate part of the nucleus, so that regions receiving a crossed input in normal rabbits receive an uncrossed input in the abnormal rabbits. Chinchilla rabbits show a slightly reduced fur pigmentation but have a normal distribution of pigment in the retinal pigment epithelium and these rabbits have normal retinogeniculate pathways.In addition, the normal retinogeniculate pathway was studied. Autoradiographic methods show that the β segment of the lateral geniculate nucleus receives a contralateral input. Hence, earlier views that this segment projects to the visual cortex but receives no retinal input, are untenable. Further, in the autoradiographic material it was not possible to identify separate ipsilateral laminae and it was concluded that in the normally pigmented rabbit the ipsilateral retinogeniculate projection forms one relatively continuous group

ISSN:0092-7317    

DOI:10.1002/cne.901590103

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractThe distribution of acetylcholinesterase (AChE) in the rat vallate papillary bud was investigated by histochemical electron microscopy. Previous reports of specific AChE activity around subgemmal and intragemmal nerves and between some taste bud cells have been confirmed. In addition we have consistently observed dense precipitation between microvilli in the taste pore. The studies suggest that the neurotransmitter, acetylcholine, may be involved in early events in the taste process which are believed to occur in the pore.

ISSN:0092-7317    

DOI:10.1002/cne.901590104

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractLight and electron microscopic observations were made on the dorsal lateral geniculate nucleus (DLGN) of 33 young adult male albino rats. Three variants of the Golgi silver impregnation technique were employed in the light microscopic studies.Neurons were classified into three categories based on location, dendritic pattern, and dendritic appendages. Type 1 and type 3 neurons were distributed throughout the DLGN. Type 2 neurons were located in the superficial zone. Dendritic appendages of type 1 and type 2 neurons indicated these cells may function as geniculocortical relay neurons. The type 3 neurons had lobulated dendritic appendages and an axon that terminated within the nucleus. Type 3 neurons may represent Golgi‐type II interneurons. Camera lucida drawings, photomicrographs, and electronmicrographs illustrate the characteristics of the three cell types. The literature on ultrastructural and neurophysiological findings may substantiate the presence of three neuronal types. Initially, the rat DLGN does not appear as elaborately organized as the nucleus observed in cats and primates; however, there are notable similarities in neuronal morphology and synaptolog

ISSN:0092-7317    

DOI:10.1002/cne.901590105

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractA stereotaxic apparatus and technique for electrode placement in forebrain nuclei of the goldfish is described. An atlas of forebrain nuclei is given. Some new nuclear regions are described and the nomenclature of several nuclei is discussed.

ISSN:0092-7317    

DOI:10.1002/cne.901590106

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractA stereotaxic apparatus and technique for electrode placement in forebrain nuclei of the killifish,Fundulus heteroclitus, is described. An atlas of forebrain nuclei is given. A new nuclear region in the telencephalon is described.

ISSN:0092-7317    

DOI:10.1002/cne.901590107

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

摘要:

AbstractThe lateral olfactory tract (LOT) of the ferret has been shown to project to most of the pyriform lobe, as in the cat. Only a small medio‐posterior region of the pyriform cortex (theangular cortex), which has a distinctly different appearance in Nissl stained sections, proves to be devoid of olfactory connections. Despite the fact that sub‐areas can be recognized within olfactory cortex, there is an underlying constancy in design throughout. Latency measurements indicate that fine collateral branches of the LOT reach the posterior olfactory cortex, whereas mainly larger diameter (faster conducting) fibres comprise the contribution to anterior olfactory cortex. Thus in the present context it is sufficient to recognise just an anterior and posterior subdivision of olfactory cortex, contingent on the above criterion and correlated with cytoarchitectural features, chiefly variations in cortical layers II and III of the regions concerned.Pyriform cortex directly in receipt of LOT fibres, and associated deeper cortical zones, generated potentials in the olfactory bulbs which can only be attributed to centrifugal input, thus further substantiating an olfactory role for this cortex. In addition, non‐cortical regions in receipt of LOT fibres, namely the anterior olfactory nucleus, olfactory tubercle, cortical amygdaloid nucleus and nucleus of the lateral olfactory tract, also contribute centrifugal input to the bulbs. All these regions are thereby capable of providing a rather direct feedback on olfactory bulb activity. The exact pathways concerned have yet to be deter

ISSN:0092-7317    

DOI:10.1002/cne.901590108

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY

ISSN:0092-7317    

DOI:10.1002/cne.901590101

出版商:The Wistar Institute of Anatomy and Biology    

年代:1975

数据来源: WILEY