Cytoarchitecture of sensorimotor areas in the cat cerebral cortex

Abstract

The organization of multiple motor areas in the cerebral cortex has been investigated frequently in primates but rarely in nonprimate species. To compare sensorimotor areas in cats and primates, the cytoarchitecture of frontal and parietal areas of the cat cerebral cortex was described and mapped from coronal sections stained with cresyl violet or thionine. Multiple subdivisions of areas 4 and 6 were recognized; of these, the cytoarchitecture of area 4 gamma is similar to that of area 4 described in other carnivores and in primates and is characterized by giant pyramidal cells in multiple rows or clusters in lamina V. In other subdivisions of area 4 (4 delta, 4sfu, and 4fu), giant pyramidal cells are few or absent in lamina V, and these subdivisions resemble area 6 of primates. Area 6 of the cat cortex is heterogeneous, and differences in laminar appearance and size of pyramidal cells in lamina V distinguish its four subdivisions (6a alpha, 6a beta, 6a gamma, and 6iffu). The adjoining prefrontal areas are distinguishable from area 6 by the presence of a thin internal granular lamina (lamina IV) and the reduced size of pyramidal cells in lamina V. Laminae are poorly differentiated in the cingulate areas, where a rostral and caudal subdivision can be distinguished on the basis of the absence or presence of lamina IV. Area 3a is characterized by a thin lamina IV and is located between frontal agranular and parietal granular (well-defined lamina IV) fields (3b, 1, 2, 2pri, 5, and 7). Insular cortex can be subdivided into granular and agranular fields.

Vagal Input to Lateral Area 3a in Cat Cortex

“…The tissue block was soaked in 10% Formalin for 1 wk, then in 30% sucrose in Formalin for 1 wk, and then cut in serial 60-m coronal frozen sections and stained with thionin. Cytoarchitectonic areas were determined using criteria based on Avendano and Verdu (1992), Ghosh (1997), Hassler and MuhsClement (1964), and Leclerc et al (1994). Digital photomicrographs were taken with a Leaf Microlumina, and the images were processed with Adobe Photoshop for adjustment of brightness and contrast as well as insertion of indications and anatomic landmarks.…”

“…With regard to this issue, cats have several advantages; they have distinctively different cytoarchitectonic areas (Avendano and Verdu 1992;Ghosh 1997;Hassler and Muhs-Clement 1964;Leclerc et al1994) with well-documented deep (area 3a) and cutaneous inputs (area 3b or S1 proper) (Felleman et al1983;Jones and Porter 1980). The S1 representation of the trigeminal intraoral region has been mapped (Iwata et al 1985;Taira 1987) and can guide localization of the vagal region (Ito 2002).…”

Widespread Distribution of Visual Responsiveness in Frontal, Prefrontal, and Prelimbic Cortical Areas of the Cat: An Electrophysiologic Investigation

“…The same series of drawings was used to illustrate the limits of cortical layer V and cytoarchitectural boundaries between areas. We used the cytoarchitectural criteria and terminology of Hassler and Muhs-Clement (1964), as modified by Avendañ o et al (1992) and Ghosh (1997b), to identify cortical areas within the cruciate sulcus, the anterior and posterior sigmoid gyri, and the lateral bank of the presylvian sulcus. Criteria proposed by Craig et al (1982) and Cavada and Reinoso-Suá rez (1985) were used to subdivide medial and lateral prefrontal areas.…”

Premotor Cortex Provides a Substrate for the Temporal Transformation of Information During the Planning of Gait Modifications

“…3). Cytoarchitectonic borders were determined based on the criteria detailed in previous studies (Hassler R and K Muhs-Clement 1964;Avendano C et al 1988;Ghosh S 1997b).…”

“…In cats, Hassler and Muhs-Clement (Hassler R and K Muhs-Clement 1964, see also Ghosh S 1997b) identified several cytoarchitectonic divisions of area 6 (generally assumed to correspond to non-primary, premotor cortex) in the agranular cortex of the frontal portion of the cerebrum, both anterior to and within the cruciate sulcus. These divisions include areas 6aα, 6aβ, 6aγ and 6iffu and are identified on a flattened diagram of the frontal cortex in Fig.…”