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L Maler

Publications and source records attributed to L Maler.

At least 91 records · Page 5Linked to original sources
PubMed1981

Laminar organization of the afferent and efferent systems of the torus semicircularis of gymnotiform fish: morphological substrates for parallel processing in the electrosensory system.

The torus semicircularis of Gymnotiform fish is an enlarged laminated midbrain structure which receives lemniscal input from electrosensory, mechanoreceptive lateral line, and auditory systems. The electrosensory input in confined to the dorsal torus, while the auditory and mechanoreceptive systems project to the ventral torus. Anterograde and retrograde techniques were used were used to determine the connections of the dorsal torus in Apteronotus and Eigenmannia. The dorsal torus can be divided into nine major laminae, each of which has distinct afferent and efferent connections. The dorsal torus receives five afferent inputs: (1) A contralateral topographic input from the posterior lateral line lobe (PLLL) projects to laminae III, V, VI, VII, VIIIB, and VIIID. (2) Eurydendroid cells of the caudal lobe of the cerebellum project contralaterally to lamina VIIIB. (3) A portion of the descending nucleus of V projects to laminae VIIIA, VIIIC, and IX. (4) Lamina I is a cap of fine myelinated fibers which may originate in the torus longitudinalis. They project to laminae II and III. (5) The ipsilateral optic tectum projects to the dorsal torus. The dorsal torus projects to six major targets: (1) Laminae VII, VIII, and IX project bilaterally to a lateral region of the diencephalon above n. preglomerulosus, herein named n. electrosensorius. An area below the dorsal thalamus receives a smaller ipsilateral projection. (2) Laminae II, V, VIvn, VII, VIII, and IX project topographically to the deeper laminae of the ipsilateral optic tectum. This projection is in spatial register with the visual map in the superficial layers of the tectum. (3) Lamina VIIID projects ipsilaterally to the lateral reticular formation. (4) All laminae other than I, VI, and VIIIB project topographically to ahe ipsilateral n. praeeminentialis, which provides a powerful descending projection to the PLLL. (5) Lamina IX projects to a dorsal pretectal area. (6) The ipsilateral inferior olive receives a projection from the dorsal torus.

Afferent Pathways↗
PubMed1981

The distribution of acetylcholinesterase and choline acetyl transferase in the cerebellum and posterior lateral line lobe of weakly electric fish (Gymnotidae).

Cholinesterase was demonstrated in the caudal lobe of the cerebellum but not the corpus cerebelli of weakly electric gymnotid fish. It had a patchy distribution in the granule cell layer and was very dense in the molecular layer; the cholinesterase staining was also dense in the contiguous molecular layer of the subjacent electrosensory region. Choline acetyltransferase was also found in far greater amounts within the electrosensory region and caudal lobe of the cerebellum than within the corpus cerebelli itself.

Acetylcholinesterase↗
PubMed1981

Hypophysiotropic neurons in the goldfish hypothalamus demonstrated by retrograde transport of horseradish peroxidase.

The horseradish-peroxidase (HRP) technique was used to visualize the cell bodies of axons projecting to the goldfish pituitary. Following intravenous injections of HRP, HRP reaction products were observed in axons of the rostral pars distalis, proximal pars distalis, neurointermediate lobe, pituitary stalk and in axons coursing from the pituitary into the hypothalamus. HRP-labelled cells in the brain were localized in two regions only - the nucleus preopticus (NPO) pars magnocellularis and pars parvocellularis, and the nucleus lateralis tuberis (NLT) of the hypothalamus. These observations suggest that the NPO and NLT are the source of the neurosecretory innervation of the goldfish pituitary.

Animals↗
PubMed1979

The posterior lateral line lobe of certain gymnotoid fish: quantitative light microscopy.

The posterior lateral line lobe of the wave species of gymnotoid fish was investigated with the Golgi technique. The posterior lobe has a laminar structure and contains II cell types differentially distributed in the varous laminae (fig. 13). The major laminae, from ventral to dorsal are the deep fiber layer, containing multipolar neurons; the deep neuropil layer, containing ovoid neurons and a sub-lamina of spherical cells; the granule cell lamina, containing two types of granule cell; the plexiform laminae; the polymorphic cell lamina, containing basilar pyramids, non-basilar pyramids, giant fusiform cells, and polymorphic cells; the stratum fibrosum; the molecular lamina, containing neurons of the ventral molecule layer and stellate cells. The spherical cells are regularly distributed in their sub-lamina and appear to receive one type of primary afferent input. Another type of primary afferent input ends in the deep neuropil and granule layers, in proximity to the basilar dendrites of the granule cells and the basilar pyramids. The basilar pyramidal cell spatially alternates with the non-basilar pyramidal cell, so that the basilar dendritic trees of nearest-neighbour basilar pyramids show almost no overlap. Descending input to the posterior lobe ends in the molecular layer, in proximity to apical dendrites of both pyramidal cells, giant fusiform cells, polymorphic cells, and one type of granule cell. There are three afferent fiber systems in the molecular layer, one running transversely, one longitudinally, and one vertically. Local circuity in the posterior lobe is precisely organized and involves projections of granule cells onto overlying pyramidal cells. The polymorphic cell may also be involved in the intrinsic circuits of the posterior lobe.

Animals↗