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T Fitzgibbon - One of the best experts on this subject based on the ideXlab platform.

  • cortical projections from the Suprasylvian Gyrus to the reticular thalamic nucleus in the cat
    Neuroscience, 2000
    Co-Authors: T Fitzgibbon
    Abstract:

    Abstract The cat’s Suprasylvian Gyrus was injected iontophoretically with either 4% wheat germ agglutinin–horseradish peroxidase, 4% dextran–fluororuby or 4% dextran–biotin. The locations of labelled fibres, presumed terminals and cell bodies were determined with the aid of a camera lucida attachment and computer aided stereometry. Cells from the crown of the Suprasylvian Gyrus project to the dorsal-most portion of the rostral half of the reticular nucleus. The region or ‘sector’ is distinct, albeit with some overlap, from the visual sector of the reticular nucleus defined by projections from adjacent extrastriate visual cortices. The projection from the Suprasylvian Gyrus to the reticular nucleus has a rough topography such that the caudal areas project to the more caudal aspects of the sector and rostral areas project to the more rostral areas of the reticular nucleus. There is a large degree of overlap of rostrocaudal projections from the Suprasylvian Gyrus within the sector, however, the projections originating from rostral sites are situated in a more ventral location compared to the projection originating from the caudal Suprasylvian Gyrus. Analysis of the distribution of biotin labelled presumptive terminals did not support the notion of ‘slabs’ or regional variation in terminal density across the mediolateral thickness of the reticular nucleus. In addition, a number of presumptive terminals were found within the internal capsule which coincided with the position of retrogradely labelled cells in the internal capsule following thalamic injections and appears to be part of the perireticular nucleus. The results suggest that the reticular nucleus may be segregated into sectors connected with modality specific cortical areas (e.g. striate and extrastriate visual areas) and nonspecific sectors connected with polymodal (e.g. area 7) cortical regions. The reticular nucleus and its connections with the Suprasylvian Gyrus may form an important link in binding eye movements to sensory integrative process through visuomotor and auditory thalamic connections.

Helmut Heinsen - One of the best experts on this subject based on the ideXlab platform.

  • Transverse magnetic resonance image of the equine brain on the level of the amygdala.
    2019
    Co-Authors: Martin J. Schmidt, Carola Knemeyer, Helmut Heinsen
    Abstract:

    ab: amygdaloid body, aci: internal carotid artery, Ans: ansate sulcus, cc: corpus callosum, cig: cingulate Gyrus, cin: cingulum, cf: column of fornix, cfo: corpus of fornix, cn: caudate nucleus (tail), crc: cerebral crus, ec: external capsule, Ecs: ectosylvian sulcus, ex: extreme capsule, fmt: mammilo-thalamic fasciculus, fsc: subcallosal fasciculus, hs: hypothalamic sulcus, ic: internal capsule, inf: infundibular stalk, ita: interthalamic adhesion, lme: external medullary lamina, lv: lateral ventricle, Mar: marginal sulcus, max: maxillary nerve, nad: nucleus anterior dorsalis thalami, nrt: reticular nucleus of the thalamus, obl: oblique Gyrus, ot: optic tract, pg: pituitary gland, put: putamen, rcc: radition of corpus callosum, Rfi: rhinal fissure, slu: Gyrus semilunaris, smt: stria medullaris thalami, ssg: Suprasylvian Gyrus, Sss: Suprasylvian sulcus, Syl: sylvian fissure, syl: sylvian Gyrus, III: oculomotor nerve, 3: third ventricle.

  • Transverse magnetic resonance image of the equine brain on the level of the diagonal band of Broca.
    2019
    Co-Authors: Martin J. Schmidt, Carola Knemeyer, Helmut Heinsen
    Abstract:

    Ans: ansate sulcus, cc: corpus callosum, cho: optic chiasm, chp: choroid plexus, cin: cingulum, cig: cingulate sulcus, cla: claustrum, cn: caudate nucleus, cso: centrum semiovale, dbb: diagonal band of broca, Dias: diagonal sulcus (Rhinencephalon), ec: external capsule, ecs: ectosylvian Gyrus, Ecs: ectosylvian sulcus, Enrh: endorhinal sulcus, ex: extreme capsule, fsc: subcallosal fasciculus, gp: globus pallidus, ic: internal capsule, icl: islands of Calleja, ins: insular cortex, log: lateral olfactory Gyrus, lot: lateral olfactory tract, lv: lateral ventricle, mar: marginal Gyrus, Mar: marginal sulcus, mca: medial cerebral artery, otb: olfactory tubercle, put: putamen, rc: rostral commissure, rcc: radiation of corpus callosum, Rfi: rhinal fissure, Scl: sulcus of corpus callosum, sl: lateral septal nuclei, sm: medial septal nuclei, Spl: splenial sulcus, ssg: Suprasylvian Gyrus, Sss: Suprasylvian sulcus, Syl: Sylvian fissure.

  • Transverse magnetic resonance image of the equine brain on the level of the caudal commissure.
    2019
    Co-Authors: Martin J. Schmidt, Carola Knemeyer, Helmut Heinsen
    Abstract:

    are: entorhinal area, alv: alveus; cam: ammon’s horn, ccd: caudal commissure, cdc: caudal colliculus, cgs: central grey substance, cha: habenular commissure, cig: cingulate Gyrus, cin: cingulum, crc: cerebral crus, crt: rubro- cerebello-thalamic tract, df: dentate fascia, ecs: ectosylvian Gyrus, Ecs: ectosylvian sulcus, Ectm: ectomarginal suclcus, flv: ventral longitudinal fasciculus, fsc: subcallosal fasciculus, lgb: lateral geniculate body, mar: marginal Gyrus, Mar: marginal sulcus, mgb: medial geniculate body, ml: medial lemniscus, obl: oblique Gyrus, or: optic radiation, ot: optic tract, pb: pineal body, pcm: peduncles of the mammillary body, pg: pituitary gland, phg: parahippocampal Gyrus, pul: pulvinar nuclei, rcc: radiation of corpus callosum, Rfi: rhinal fissure, rn: red nucleus, scc: splenium of corpus callosum, snr: substantia nigra, Spl: splenial sulcus, ssg: Suprasylvian Gyrus, Sspl: suprasplenial sulcus, Sss: Suprasylvian sulcus, vtd: ventral tegmental decussation.

  • Transverse magnetic resonance image of the equine brain on the level of the septal nuclei.
    2019
    Co-Authors: Martin J. Schmidt, Carola Knemeyer, Helmut Heinsen
    Abstract:

    acn: accumbens nucleus, Ans: ansate sulcus, cig: cingulate Gyrus, cin: cingulum, cla: claustrum, cn: caudate nucleus (caput), Cor: coronal sulcus, cso: centrum semiovale, Dia: diagonal sulcus, ec: external capsule, ecs: ectosylvian Gyrus, Ecs: ectosylvian sulcus, ex: extreme capsule, fsc: subcallosal fasciculus, gcc: genu of the corpus callosum, Gen: genual sulcus, ic: internal capsule, lot: lateral olfactory tract, opn: optic nerve, otb: olfactory tubercle, put: putamen, rca: rostral cerebral artery, rcc: radiation of the corpus callosum, Rfi: rhinal fissure, sl: lateral septal nuclei, ssg: Suprasylvian Gyrus, Sss: Suprasylvian sulcus, syl: sylvian Gyrus.

  • Parasagittal magnetic resonance image of the equine brain at the level of the optic radiation.
    2019
    Co-Authors: Martin J. Schmidt, Carola Knemeyer, Helmut Heinsen
    Abstract:

    ab: amygdaloid body, ans: ansiform lobule, are: entorhinal aera, cam: ammon’s horn, chp: choroid plexus, Dia: diagonal sulcus, ec: external capsule, flo: flocculus, gg: Gasserian ganglion, ic: internal capsule, lgb: lateral geniculate body, max: maxillary nerve, mgb: medial geniculate body, nd: dentate nucleus, ob: olfactory bulb, olf: olfactory fibres, opth: ophthalmic nerve, or: optic radiation, paf: paraflocculus, Prr: prorean sulcus, Prs: presylvian sulcus, put: putamen, qdr: quadrangulare lobule, rcp: rostral cerebellar peduncle, Rfi: rhinal fissure, ssg: Suprasylvian Gyrus, Sss: Suprasylvian sulcus, V: trigeminal nerve, VII: facial nerve, VIII: vestibulocochleal nerve.

E I Rodionova - One of the best experts on this subject based on the ideXlab platform.

  • two visual areas located in the middle Suprasylvian Gyrus cytoarchitectonic field 7 of the cat s cortex
    Neuroscience, 1998
    Co-Authors: Ivan N Pigarev, E I Rodionova
    Abstract:

    Abstract Neuronal properties and topographic organization of the middle Suprasylvian Gyrus (cortical cytoarchitectonic field 7) were studied in three behaving cats with painlessly fixed heads. Two main neuronal types were found within this field. Type 1 neurons occupied the lateral part of the field and bordered representation of directionally selective neurons of the lateral Suprasylvian visual area by vertical retinal meridian. Type 1 neurons had elongated and radially oriented receptive fields located in the lower part of contralateral visual field. Type 1 neurons preferred stimuli moving out or to the centre of gaze at a low or moderate speed, and many of them were depth selective. The responses were enhanced by attention, oriented to the presented stimulus. Medial part of the field 7 along the border with the area V3 was occupied by neurons with not elongated receptive fields (type 2). These neurons preferred moderate and high speeds of motion, and gratings of proper spatial frequency and orientation were effective stimuli for them. Border between representations of type 2 and type 1 neurons coincided with projection of horizontal retinal meridian. At the rostral and caudal borders of the field 7 abrupt changes of neuronal properties took place. Neurons which abutted field 7 anteriorly and posteriorly resembled hypercomplex cells and their small receptive fields were located in the central part of the visual field. Topographical considerations and receptive field properties allowed us to conclude that the medial part of the field 7 (included type 2 neurons) is functionally equivalent to the area V4 in the cortex of primates, while the lateral part (type 1 neurons) may correspond to the area V4T.

Kenichi Matsunami - One of the best experts on this subject based on the ideXlab platform.

  • neuronal responses to vestibular and callosal stimulation in the anterior Suprasylvian Gyrus of the cat
    Neuroscience Research, 1993
    Co-Authors: Hirotaka Satake, Takashi Kawashima, Masataka Suzuki, Kenichi Matsunami
    Abstract:

    Abstract Neuronal responses to electrical stimulation at the horizontal ampulla (HA), vestibular nerve (at the windows) and corpus callosum (CC) were investigated in neurons in the anterior Suprasylvian Gyrus of the cat. The field potentials to HA stimulation had short latency: 2.9 ± 0.3 (mean ± SD) ms from the stimulus to the onset and 5.6 ± 1.9 ms to the peak. The focus of the evoked potentials was located in the anterior Suprasylvian (ASS) Gyrus or near the ASS sulcus. HA stimulation activated 6 neurons out of 674 examined, with the mean latency of 4.3 ± 1.1 ms. Of these 6, four neurons also responded to window stimulation. Fifty-six neurons responded to window stimulation with the mean latency of 6.1 ± 2.4 ms. The mean latency for CC stimulation was 1.9 ± 0.9 ms ( n = 76). Four neurons responded to CC stimulation antidromically (mean = 0.9 ± 0.3 ms) and one of them also responded orthodromically. The convergence of CC inputs in relation to HA or window stimulation was examined. One (17%) of the 6 HA-activated cells responded to CC stimulation, compared with 8 (14%) of the 56 neurons activated by window stimulation. The other 612 neurons did not respond to either HA or window stimulation, and 80 (13%) of the 612 responded to CC stimulation. Therefore, it is concluded that neurons in the ASS Gyrus received callosal input equally irrespective of the presence or absence of responses to ampulla or window stimulation. WGA-HRP was injected in the ASS Gyrus to identify the passing callosal fibers in the CC. Fibers from the ASS area passed at the rostral third of the CC. The present results indicate that the ASS area received vestibular projection with short latency, but responses of this projection did not seem to be very strong, at least from the present unit study, to HA stimulation. Discussion was made on the poor neuronal responses to electrical HA stimulation in comparison with previous studies. Also consideration was made on neuronal activity to CC stimulation.

Martha E Bickford - One of the best experts on this subject based on the ideXlab platform.

  • ultrastructural analysis of projections to the pulvinar nucleus of the cat i middle Suprasylvian Gyrus areas 5 and 7
    The Journal of Comparative Neurology, 2005
    Co-Authors: Zsolt B Baldauf, Ranida Chomsung, Breckinridge W Carden, Paul J May, Martha E Bickford
    Abstract:

    The mammalian pulvinar nucleus (PUL) establishes heavy interconnections with the parietal lobe, but the precise nature of these connections is only partially understood. To examine the distribution of corticopulvinar cells in the cat, we injected the PUL with retrograde tracers. Corticopulvinar cells were located in layers V and VI of a wide variety of cortical areas, with a major concentration of cells in area 7. To examine the morphology and distribution of corticopulvinar terminals, we injected cortical areas 5 or 7 with anterograde tracers. The majority of corticopulvinar axons were thin fibers (type I) with numerous diffuse small boutons. Thicker (type II) axons with fewer, larger boutons were also present. Boutons of type II axons formed clusters within restricted regions of the PUL. We examined corticopulvinar terminals labeled from area 7 at the ultrastructural level in tissue stained for gamma-aminobutyric acid (GABA). By correlating the size of the presynaptic and postsynaptic profiles, we were able to quantitatively divide the labeled terminals into two categories: small and large (RS and RL, respectively). The RS terminals predominantly innervated small-caliber non-GABAergic (thalamocortical cell) dendrites, whereas the RL terminals established complex synaptic arrangements with dendrites of both GABAergic interneurons and non-GABAergic cells. Interpretation of these results using Sherman and Guillery's recent theories of thalamic organization (Sherman and Guillery [1998] Proc Natl Acad Sci U S A 95:7121-7126) suggests that area 7 may both drive and modulate PUL activity.