Am. Castelfranco et al., DETAIL, PROPORTION, AND FOCI AMONG FACE RECEPTIVE-FIELDS OF CLIMBING FIBER RESPONSES IN THE CAT CEREBELLUM, Somatosensory & motor research, 11(1), 1994, pp. 27-46
This paper reports a theoretical analysis of the transformation from a
tactile stimulus of the face to climbing fiber responses in three reg
ions of the cat cerebellum. The database consisted of climbing fiber r
eceptive fields on the face from 75 responses from the anterior lobe,
33 responses from the paramedian lobule (PML), and 52 responses from t
he crus IIp of the anesthetized cat. The receptive fields were similar
in being composed of discrete areas on the skin, or skin compartments
. The regional differences in the configurations of the receptive fiel
ds were reflected in which compartments most often combined to form re
ceptive fields. Each region had a distinct pattern of the preponderanc
e of skin compartments that combined to form receptive fields, and yet
the preponderant compartments were all chosen from one composite set
of compartments that applied to all three regions. The climbing fiber
representation of the face differed over the three regions (1) in the
parts of the face that were represented; (2) in the frequency with whi
ch certain areas were included in the receptive fields; and (3) in the
details of the face that could be distinguished by differing ensemble
s of climbing fiber responses. The majority of the climbing fiber rece
ptive fields from either the anterior lobe or the crus IIp were unique
to the region, whereas the majority of the receptive fields of respon
ses from the PML were encountered in one or both of the other regions.
Overlapping all face receptive fields from each of the three regions
revealed that the receptive fields were differentially focused on or a
round the cornea, nose, or chin. In the anterior lobe, the face recept
ive fields mainly included the chin (43%) and the glabrous tip of the
nose (40%), but few included the cornea (1%). In the PML, the receptiv
e fields included the cornea (24%) and the chin (58%), but none includ
ed the nose. In the crus IIp, the cornea was included in the greatest
number (37%) of receptive fields, whereas the nose and the chin were i
ncluded equally (24%). The different sets of climbing fiber receptive
fields in each of the three regions afforded the regions differing abi
lities to distinguish among complex patterns of stimuli, depending on
the portion of the face stimulated.