Correlations between the receptive field properties and morphology of neurons in the deep layers of the hamster's superior colliculus.
Extracellular and intracellular recording, receptive field mapping, and intracellular HRP injection techniques were used to define the morphological classes of cells in the deep laminae of the hamster's superior colliculus and to determine whether there are any correlations between the structural and functional characteristics of these neurons. A total of 110 neurons were characterized and reconstructed. Of these, 23.6% (N = 26) were visual, 60% (N = 66) were somatosensory, 0.9% (N = 1) were bimodal (visual-somatosensory), and 15.4% (N = 17) were unresponsive. Of the somatosensory neurons, 72.7% (N = 48) were low threshold, 4.5% (N = 3) had a wide dynamic range, 9.1% (N = 6) responded only to noxious stimulation, and 13.6% (N = 9) had complex somatosensory receptive fields. Deep layer cells were divided into eight morphological classes. These classes were multipolar cells (26.4%, N = 29), bipolar cells (9.1%, N = 10), widefield vertical cells (7.3%, N = 8), horizontal cells (13.6%, N = 15), stellate cells (10.9%, N = 12), ventrally directed cells (5.5%, N = 6), sparse radial cells (17.3%, N = 19), and small sparse radial cells (6.4%, N = 7). Four cells (3.6%) did not fit into this classification scheme. Univariate and multivariate analyses of variance of properties such as soma area, number of branch points, total dendritic length, and volume and orientation of dendritic arbor indicated that these classes were significantly different. However, chi 2 analysis and multivariate analysis of variance indicated no significant relationships between morphological class and either laminar location or receptive field type. There was a significant positive relationship between the possession of dendrites that extended into the superficial laminae and visual responsivity.
Mooney
R D
RD
Department of Anatomy, Medical College of Ohio, Toledo 43699.
Nikoletseas
M M
MM
King
T D
TD
Savage
S V
SV
Huang
X
X
D000818:Animals; D006224:Cricetinae; D003712:Dendrites / Q000502:physiology / Q000648:ultrastructure; D004594:Electrophysiology; D006651:Histocytochemistry; D006735:Horseradish Peroxidase; D007478:Iontophoresis; D009474:Neurons / Q000502:physiology*; D010812:Physical Stimulation; D011984:Sensory Receptor Cells / Q000502:physiology*; D013477:Superior Colliculi / Q000166:cytology* / Q000502:physiology; D014794:Visual Fields / Q000502:physiology
D006735:Horseradish Peroxidase