Tectal and thalamic projections of dorsal column and lateral cervical nuclei: a quantitative study in the cat

Blomqvist, Anders; Flink, Roland; Bowsher, David; Griph, Sverker; Westman, Jan

doi:10.1016/0006-8993(78)90202-0

Cited by 85 publications

(36 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Part of the DCN neurons projecting to the thalamus also send collaterals to other brainstem targets, such as the cochlear nuclei, the inferior colliculus, and the pontine nuclei (Kosinski et al, 1988;Li and Mizuno, 1997a, b). Most of the remaining targets of DCN projections (pretectal area, superior colliculus, cerebellum, and spinal cord) arise from cells not projecting to the diencephalon, which form a minor fraction of all DCN neurons (Blomqvist et al, 1978;Berkley et al, 1986;Yoshida et al, 1992). Our findings confirm that thalamus and cerebellum receive afferents from separate, albeit partially intermingled, cell populations of DCN (Mantle-St. John and Tracey, 1987).…”

Section: On the Varieties Of Projection Neurons And Neuron Numberssupporting

confidence: 86%

“…The volume of the DCN was also determined by the Cavalieri method. The cat is the only other species for which similar quantitative studies have been carried out (Blomqvist et al, 1978;Blomqvist, 1980;Ellis and Rustioni, 1981;Rustioni et al, 1984;Wiberg and Blomqvist, 1984;Heino and Westman, 1991;Avendañ o and Dykes, 1996b), and these were helpful in evaluating our results in the rat. The precision of the estimates for each rat was evaluated, and the contribution of the methodological "noise" to the observed interindividual variability was determined.…”

mentioning

confidence: 88%

See 1 more Smart Citation

Quantitative stereological evaluation of the gracile and cuneate nuclei and their projection neurons in the rat

Bermejo

Jiménez

Torres

et al. 2003

J of Comparative Neurology

102

View full text Add to dashboard Cite

Stereological methods were employed to estimate the volume and neuron numbers of the rat dorsal column nuclei (DCN). These methods were applied to Nissl-stained sections from control animals and cases that received injections of horseradish peroxidase in the thalamus, the cerebellum, or the spinal cord. Additional cases received combinations of fluorescent tracers in the same structures, to examine whether some of the retrogradely labeled neurons sent collaterals to different targets. The mean volume of the DCN is 0.81 mm(3) (range 0.65-1.10 mm(3)), of which 3%, 39%, and 59% correspond, respectively, to the nucleus of Bischoff (Bi), the gracile (Gr), and the cuneate (Cu) nuclei. Within Cu, the middle division (CuM) is the largest (42%), followed by the rostral (CuR; 36%) and caudal (CuC; 22%) divisions. The mean total number of neurons in the DCN is 16,000 (range 12,400-19,500), of which 2.4%, 34.0% and 63.6% correspond, respectively, to Bi, Gr, and Cu. Within Cu, CuM contains 48% of all neurons, and 27% correspond to CuR and 25% to CuC. Interanimal variability is moderate for the whole DCN and Cu but increases when individual nuclei are considered. About 80% of DCN neurons project to the thalamus, 3% to the spinal cord, and 7% to the cerebellum. Thalamic-projecting cells are more numerous in CuM and Gr (83%), and relatively less common in Bi and CuC (72-74%). Most of the DCN neurons projecting to the spinal cord appear in CuC and CuM. Two-thirds of the neurons projecting to the cerebellum are located in CuR, 20% in CuM, and 15% in Gr. A small fraction of neurons projects simultaneously to spinal cord and thalamus.

show abstract

Section: On the Varieties Of Projection Neurons And Neuron Numberssupporting

confidence: 86%

mentioning

confidence: 88%

Quantitative stereological evaluation of the gracile and cuneate nuclei and their projection neurons in the rat

Bermejo

Jiménez

Torres

et al. 2003

J of Comparative Neurology

102

View full text Add to dashboard Cite

show abstract

“…This 'cell clusters' region has been demonstrated by the use of anterograde degeneration techniques to be the site of termination of the somatotopically organized primary afferent projection (Kuypers & Tuerk, 1964;Hand, 1966;Rustioni & Macchi, 1968;Keller & Hand, 1970), and primary afferent terminals have been identified at the electron microscopic level in both the nucleus gracilis (Blomquist & Westman, 1970;Rustioni & Sotelo, 1974) and nucleus cuneatus (Walberg, 1965(Walberg, , 1966. Furthermore, studies with the retrograde transport of horseradish peroxidase (HRP) have identified thalamic projection neurons (TPN) as the large, round neurons arranged in the characteristic cell clusters (Berkley, 1975;Blomquist & Westman, 1975;Cheek et aI., 1975;Blomqvist et al, 1978;Blomquist, 1980;. In contrast, rostral and caudal regions of the DCN, as well as the area of the nuclei ventral to the cell clusters, are characterized by multipolar or fusiform neurons with long radiating dendrites (Kuypers & Tuerk, 1964;Hand, 1966).…”

Section: Introductionmentioning

confidence: 95%

Thalamic projecting neurons in the feline nucleus cuneatus. A combined horseradish peroxidase and high voltage electron microscopic study

1982

View full text Add to dashboard Cite

The retrograde transport of horseradish peroxidase (HRP) has been employed to identify thalamic projection neurons (TPN) in the feline nucleus cuneatus by means of light microscopy and high voltage electron microscopy. Forty-eight hours after injection of HRP in the contralateral ventrobasal complex of the thalamus, labelled neurons at levels caudal to the obex are concentrated in the cell clusters of the dorsal two-thirds of the nucleus. In plastic sections, labelled TPN are identified by the presence of HRP-positive granules in the perinuclear cytoplasm. TPN are typically about 25 micrometers in diameter, have a round nucleus with a smooth contour and abundant cytoplasm. In contrast, neurons unlabelled after thalamic injection are located at the periphery of clusters of TPN. Unlabelled neurons are characterized by their fusiform shape (hence, round when encountered in cross-section), small diameter (10-15 micrometers), a nucleus with an irregular or highly indented contour, and sparse cytoplasm. At the ultrastructural level, TPN are identified by the presence of HRP-positive, membrane-bound, dense bodies in the perinuclear cytoplasm. Furthermore, the presence of such dense bodies in cross-sections of dendrites allows their identification as processes of TPN. The perikarya of adjacent neurons in a cluster are often closely apposed and separated by an extracellular space of 20 to 25 nm. Adjacent to such sites of apposition, small boutons are often presynaptic to one or both of the neurons. The possible functional implications of such an arrangement are discussed.

show abstract

“…It is now well established that several somatosensory ascending pathways project to various structures of the dorsal mesencephalon in the cat (Fields, Clanton & Anderson, 1977;Baleydier & Mauguiere, 1978;Blomqvist, Flink, Bowsher, Griph & Westman, 1978;Edwards, Ginsburgh, Henkel & Stein, 1979;Flink, Wiberg & Blomqvist, 1983;Bj6rkeland & Boivie, 1984a, b, 1985Itoh, Kaneko, Kudo & Mizuno, 1984;Wiberg & Blomqvist, 1984 a b;Cooper & Dostrovsky, 1985;Wiberg, Westman & Blomqvist, 1986;Yezierski & Schwartz, 1986;Yezierski, 1988). The region is important for vision and hearing.…”

Section: Introductionmentioning

confidence: 99%

The somatosensory intercollicular nucleus of the cat's mesencephalon.

Blomqvist

Danielsson

Norrsell

1990

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Unitary, neural activity was sampled with tungsten electrodes in the mesencephalic, intercollicular region of cats anaesthetized with chloralose. The units' stereotaxic co-ordinates were noted and they were tested for activation by adequate tactile, visual and acoustic stimuli as well as electrical nerve stimulation. The units' geometrical gradations were afterwards translated into morphological terms by means of unbiased, cytoarchitectonic identifications of those structures which had been penetrated by the electrodes.2. The primary objectives were the conventional, somatosensory units, which had reliable, low-threshold, tactile receptive fields and could not be activated by the two other types of adequate stimulation. There were 139 such units from a total sample of 495.3. These somatosensory units were found to occupy many of the region's structures, notably the intercollicular nucleus (INC), the nucleus of the brachium of the inferior colliculus, the stratum griseum intermedium and the stratum griseum profundum of the superior colliculus. INC was the only structure which had an exclusively somatosensory input.4. The units of INC had tactile receptive fields varying between one and several hundred square centimetres. Convergence of afferent input from outside these fields could sometimes be demonstrated by nerve stimulation. The latencies of activation from the contralateral sciatic nerve were, on average, shorter for units of INC than for the somatosensory units of the other intercollicular structures, and INC units could also follow higher stimulation frequencies.5. The findings support the assumption that INC may constitute a distinct mesencephalic centre for somatosensory function.

show abstract

Tectal and thalamic projections of dorsal column and lateral cervical nuclei: a quantitative study in the cat

Cited by 85 publications

References 17 publications

Quantitative stereological evaluation of the gracile and cuneate nuclei and their projection neurons in the rat

Quantitative stereological evaluation of the gracile and cuneate nuclei and their projection neurons in the rat

Thalamic projecting neurons in the feline nucleus cuneatus. A combined horseradish peroxidase and high voltage electron microscopic study

The somatosensory intercollicular nucleus of the cat's mesencephalon.

Contact Info

Product

Resources

About