The Pretectal Complex of the Rabbit: Distribution of Acetylcholinesterase and Reduced Nicotinamide Adenine Dinucleotide Diaphorase Activities

Abstract

The chemoarchitecture of the pretectal complex of the rabbit was examined in sections stained by acetylcholinesterase (AChE) and reduced nicotinamide adenine dinucleotide (NADH) diaphorase in the coronal, horizontal and sagittal plane. Twelve different subdivisions can be identified in the rabbit prectectum on the basis of the distribution of both histochemical markers. According to the standard terminology, the pretectal complex of the rabbit consists of: the nucleus of the optic tract; the anterior, posterior, olivary and medial pretectal nuclei; the nucleus of the posterior commissure; the periventricular subcommissural gray; the suprageniculate and internal suprageniculate nuclei, and the dorsal, lateral and medial terminal nuclei of the accessory optic system. The combined use of several sectioning planes and the histochemical mapping of AChE and NADH diaphorase have been of value in resolving the structural limits within transitional regions of the pretectum.

Prosomeric map of the lamprey forebrain based on calretinin immunocytochemistry, nissl stain, and ancillary markers

“…Rendahl (1924), construing on Palmgren's (1921) previous work on the vertebrate midbrain, clearly defined the synencephalic (pretectal) limits mes/p1 and p1/p2. He also demonstrated the internal subdivision of the pretectum into precommissural and commissural parts, with some insights as well on the juxtacommissural portion later postulated in detail by our group (Martínez-de-la-Torre, 1985;Díaz, 1991;Caballero-Bleda et al, 1992;Medina et al, 1993Medina et al, , 1994Puelles et al, 1996). Rendahl (1924) also first recognized the zona limitans intrathalamica as a segmental limit between the anterior parencephalon (p3) and posterior parencephalon (p2).…”

“…As in other vertebrates, it is a complex primordium, which can be subdivided into dorsoventral tiers, anteroposterior compartments, and radially superposed strata (the latter, but not the two former types of subdivision, were already recognized in previous literature). The caudal boundary with the pretectum is approximated by (but does not exactly coincide with) the course of the fasciculus retroflexus, since it was detected cyto-and chemoarchitectonically just caudal to it (as also found by us and others in mammals; Keyser, 1972;Puelles et al, 1992;Caballero-Bleda et al, 1992;Puelles and Verney, 1998). Its rostral boundary is the zona limitans intrathalamica, which is detected generally in gnathostomes (Puelles, 1995;MacDonald et al, 1994;Barth and Wilson, 1995;Puelles et al, 1996;.…”

“…According to our analysis, the pretectum of lampreys contains in nuce all the primordial portions distinguished in tetrapods (precommissural, juxtacommissural, and commissural alar portions of p1; Martínez-de-la-Torre, 1985;Caballero-Bleda et al, 1992;Puelles et al, 1996). It overlies a standard subpretectal (prerubral) tegmentum (basal and floor plates of p1), which contains the nucleus of the medial longitudinal fasciculus (NMLF) and Mü ller cells 1 and 2.…”

“…An anteroposterior subdivision of the sauropsid and mammalian pretectum into comparable precommissural, juxtacommissural, and commissural portions has been reported (Martínez-de-la-Torre, 1985;Martínez, 1987;Caballero-Bleda et al, 1992;Medina et al, 1993Medina et al, , 1994Puelles et al, 1996). The migrated retinorecipient formation known as corpus geniculatum lateralis in the lamprey (Kuhlenbeck, 1977;De Miguel et al, 1990) is interpreted by us, under the descriptive name ''superficial precommissural nucleus,'' as a pretectal geniculate formation, as commonly found in tetrapods .…”

Identification of the Anterior Nucleus of the Ansa Lenticularis in Birds as the Homolog of the Mammalian Subthalamic Nucleus

“…Although a mammalian homolog of SpL has not been definitively identified (Reiner et al, 1984(Reiner et al, , 1998aCaballero-Bleda et al, 1992;Lagares et al, 1994), several lines of evidence indicate that SpL in birds is the target of an additional direct striatal output and is thereby analogous to mammalian GPi (Reiner et al, 1984(Reiner et al, , 1998aMedina et al, 1999). As is true of the GPi-like cell groups in mammals (i.e., GPi itself and SNr), SpL neurons are GABAergic, receive input from SP ϩ striatal neurons as well as from dorsal pallidal neurons that receive ENK ϩ striatal input (i.e., GPe-like pallidal neurons), and are notably enriched in GluR4 (Karten and Dubbeldam, 1973;Reiner et al, 1982aReiner et al, , 1984Veenman and Reiner, 1994;Reiner, 1996, 1997; Pa- Karten and Hodos (1967).…”