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A study of double-labeled retinal ganglion cells from the superior colliculi after unilateral eye removal in the albino rat
S198
AHMED
A STUDY OF DOUBLE-LABELED RETINAL GANGLION CELLS FROM THE SUPERIOR COLLICULI AFTER UNILATERAL EYE REMOVAL IN THE ALBINO RAT. A.K.M. FARID AND TAKASHI YAMADORI, 1st. Dept. of Anat., Kobe Univ. Sch. of Med., 7-5-1, Kusunoki-cho,
Chuo-Ku,
Kobe, 650, Japan.
1706
We studied the distribution pattern and percentage of bilaterally projecting, double-labeled retinal ganglion cells after unilateral eye removal in the albino rat by the retrograde fluorescent double labeling. Twenty albino (Wistar, Japan Clea) rats of either sex, dividing into three groups ( 1) eye removed on Day 0 (2) eye removed on Day 5 and of (3) normal adult control, were used. With the rats 3 to 4 months after eye removal, under deep anesthesia, we pressure injected 0.02 ~1 of 15% Evans Blue (EB) and 0.02 /*l of 4% Fluoro-Gold (FG) into the right and left superior colliculi, respectively. The animals were perfused with formol-saline 48 to 72 h later and the brain and eyeballs were excised. Then the brain was sectioned and the retina was removed and extended on the glass slide. Double-labeled cells were found in the ventral temporal crescent with few scattered cells in the ventral nasal quadrant for the both 0 and 5 days unilateral eye removed rats; only in the ventral temporal crescent for the normal control rats. The percentages of double-labeled retinal ganglion cells of those eye removed at days 0 and 5, and in the normal control were 64.8, 80.6, and 39.1, respectively. It was more in eye removed than in normal control and in 5 days eye removed than in O-day eye removed rat.
1707
TOPOGRAPHIC LOCALIZATION OF NEURONS PROJECTING TO THE VISUAL CORTEX IN THE PEDUNCULOPONTINE TEGMENTAL NUCLEUS (PPT) AND THE LATERODORSAL TEGMENTAL NUCLEUS (LDT) OF THE CAT. ) Div. Mnrpboloalcal [email protected] Univ. Graduate Sch. of &&Cal SclenceS, Honio 2-2-1, Kul[liamoto 860 Ja The PPT and LDT give rise cholinergic projections to various structures such as the lateral geniculate nucleus at the diencephalon level and the superior colliculus at the midbrain. However, the topographic connections of the PPT and LDT with their target structures are indistinct. In the present study, it is clarified that the PPT and LDT project directly to the visual cortex with a topographic fashion. The injection of WGA-HRP into the caudal visual cortex (Area 17) produced retrogradely labeled cells exclusively in the caudal half of the PPT and LDT with ipsilateral predominance. In the case of WGA-HRP injection into the rostra1 visual cortex (Areas 17 and 18), labeled cells were distributed almost the same as in the caudal injection All positive cells in the nuclei were not cholinergic nor serotonergic. Previous case. studies have shown that various neurochemicals are found in the PPT and LDT; especially, catecolaminergic cells are concentrated in the caudal part of the nuclei. It is indicated that the PPT and LDT neurons projecting directly to the visual cortex are restricted to the caudal part of the nuclei and that they are not cholinergic nor serotonergic, but may be catecolaminergic. Moreover, on the basis of the present data, it is suggested that the PPT and LDT are divided into at least two parts.
1708
THE INTRA-AREAL THE CAT.
MASAO
PROJECTIONS IN THE LATERAL SUPRASYLVIAN CORTEX (LS) OF NORITA, KAEKO HOSHINO AND MASAHIKO KASE. Dept. of Anat,
Niisrata Univ. Sch. of Med., Niieata. NiiPata 951. laoan
LS is known to have numerous interconnections with visual cortical areas as well as with subcortical structures implicated in visually-guided behaviors. In contrast, little data is available regarding connections within LS itself. In order to obtain information about intra-area1 connections, the anterograde tracer (biocytin) was injected into various loci along the medial and lateral banks of LS of the cats. Both medial and lateral bank injections produced label contained within the respective bank that extended rostrally and caudally from the injection site. In addition, following medial bank injections, considerable label was distributed throughout the fundus and, to a lesser extent, in the lateral bank. In contrast, no label could be detected in the medial bank after lateral bank injections, and, although label was observed in the fundus, it was restricted to the most lateral aspects. It is likely that input derived from various visual cortical areas which project to the medial bank of LS has access to this intra-area1 circuitry. This may provide a route by which visual cortical information can be relayed to other cortical and subcortical structures involved in visually-guided behaviors such as the anterior ectosylvian visual cortex, striatum, and the deep layers of the superior colliculus, despite the fact that these structures themselves do not receive substantial direct projections from the visual cortical areas that are associated with the medial bank.
AHMED
A STUDY OF DOUBLE-LABELED RETINAL GANGLION CELLS FROM THE SUPERIOR COLLICULI AFTER UNILATERAL EYE REMOVAL IN THE ALBINO RAT. A.K.M. FARID AND TAKASHI YAMADORI, 1st. Dept. of Anat., Kobe Univ. Sch. of Med., 7-5-1, Kusunoki-cho,
Chuo-Ku,
Kobe, 650, Japan.
1706
We studied the distribution pattern and percentage of bilaterally projecting, double-labeled retinal ganglion cells after unilateral eye removal in the albino rat by the retrograde fluorescent double labeling. Twenty albino (Wistar, Japan Clea) rats of either sex, dividing into three groups ( 1) eye removed on Day 0 (2) eye removed on Day 5 and of (3) normal adult control, were used. With the rats 3 to 4 months after eye removal, under deep anesthesia, we pressure injected 0.02 ~1 of 15% Evans Blue (EB) and 0.02 /*l of 4% Fluoro-Gold (FG) into the right and left superior colliculi, respectively. The animals were perfused with formol-saline 48 to 72 h later and the brain and eyeballs were excised. Then the brain was sectioned and the retina was removed and extended on the glass slide. Double-labeled cells were found in the ventral temporal crescent with few scattered cells in the ventral nasal quadrant for the both 0 and 5 days unilateral eye removed rats; only in the ventral temporal crescent for the normal control rats. The percentages of double-labeled retinal ganglion cells of those eye removed at days 0 and 5, and in the normal control were 64.8, 80.6, and 39.1, respectively. It was more in eye removed than in normal control and in 5 days eye removed than in O-day eye removed rat.
1707
TOPOGRAPHIC LOCALIZATION OF NEURONS PROJECTING TO THE VISUAL CORTEX IN THE PEDUNCULOPONTINE TEGMENTAL NUCLEUS (PPT) AND THE LATERODORSAL TEGMENTAL NUCLEUS (LDT) OF THE CAT. ) Div. Mnrpboloalcal [email protected] Univ. Graduate Sch. of &&Cal SclenceS, Honio 2-2-1, Kul[liamoto 860 Ja The PPT and LDT give rise cholinergic projections to various structures such as the lateral geniculate nucleus at the diencephalon level and the superior colliculus at the midbrain. However, the topographic connections of the PPT and LDT with their target structures are indistinct. In the present study, it is clarified that the PPT and LDT project directly to the visual cortex with a topographic fashion. The injection of WGA-HRP into the caudal visual cortex (Area 17) produced retrogradely labeled cells exclusively in the caudal half of the PPT and LDT with ipsilateral predominance. In the case of WGA-HRP injection into the rostra1 visual cortex (Areas 17 and 18), labeled cells were distributed almost the same as in the caudal injection All positive cells in the nuclei were not cholinergic nor serotonergic. Previous case. studies have shown that various neurochemicals are found in the PPT and LDT; especially, catecolaminergic cells are concentrated in the caudal part of the nuclei. It is indicated that the PPT and LDT neurons projecting directly to the visual cortex are restricted to the caudal part of the nuclei and that they are not cholinergic nor serotonergic, but may be catecolaminergic. Moreover, on the basis of the present data, it is suggested that the PPT and LDT are divided into at least two parts.
1708
THE INTRA-AREAL THE CAT.
MASAO
PROJECTIONS IN THE LATERAL SUPRASYLVIAN CORTEX (LS) OF NORITA, KAEKO HOSHINO AND MASAHIKO KASE. Dept. of Anat,
Niisrata Univ. Sch. of Med., Niieata. NiiPata 951. laoan
LS is known to have numerous interconnections with visual cortical areas as well as with subcortical structures implicated in visually-guided behaviors. In contrast, little data is available regarding connections within LS itself. In order to obtain information about intra-area1 connections, the anterograde tracer (biocytin) was injected into various loci along the medial and lateral banks of LS of the cats. Both medial and lateral bank injections produced label contained within the respective bank that extended rostrally and caudally from the injection site. In addition, following medial bank injections, considerable label was distributed throughout the fundus and, to a lesser extent, in the lateral bank. In contrast, no label could be detected in the medial bank after lateral bank injections, and, although label was observed in the fundus, it was restricted to the most lateral aspects. It is likely that input derived from various visual cortical areas which project to the medial bank of LS has access to this intra-area1 circuitry. This may provide a route by which visual cortical information can be relayed to other cortical and subcortical structures involved in visually-guided behaviors such as the anterior ectosylvian visual cortex, striatum, and the deep layers of the superior colliculus, despite the fact that these structures themselves do not receive substantial direct projections from the visual cortical areas that are associated with the medial bank.