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PubMed1992

Isolation and characterization of a library of cDNA clones that are preferentially expressed in the embryonic telencephalon.

In order to isolate genes involved in development of the mammalian telencephalon we employed an efficient cDNA library procedure. By subtracting an adult mouse telencephalic cDNA library from an embryonic day 15 (E15) mouse telencephalic cDNA library we generated two subtracted libraries (ES1 and ES2). We estimate that ES1 contains between 200 and 600 different cDNA clones, which approximates the number of genes that are preferentially expressed in the E15 telencephalon, compared to the adult telencephalon. Northern analysis of 20 different cDNA clones shows that 14 of these are expressed at least 5-fold more in the E15 telencephalon than the adult telencephalon. Limited sequencing of the 14 differentially expressed clones reveals that 10 have no significant identity to sequences in GenBank and EMBL databases, whereas the other 4 have significant sequence identity to vimentin, histone 3.3, topoisomerase I and the B2 repeat element. In situ hybridization using one of the differentially expressed cDNAs, TES-1, demonstrates that it is transiently expressed in the anlage of the basal ganglia. In situ hybridization with another differentially expressed cDNA clone, TES-4, shows that it is specifically expressed in differentiating cells of the neural axis with a distinctive rostral-caudal temporal pattern. These findings, and the methods that we have developed, provide a framework for future investigations of the genetic control of telencephalon development.

Animals↗
PubMed1997

Early molecular specification in the hippocampal rudiment: isolation of genes expressed in a region-specific manner in the embryonic telencephalon.

During development, the structure of the telencephalon is dramatically transformed by region-specific proliferation and differentiation of neuroepithelial cells. To understand mechanisms of morphogenesis in the telencephalon, a search was made for genes expressed in a region-specific manner in the dorsal telencephalon of embryonic rats. Dorso-lateral and dorso-medial portions of the telencephalon were taken from rat fetuses on embryonic day (E) 13. Genes expressed in each portion were compared by a modified differential display method. Among more than 4000 cDNA fragments, four fragments termed M1, M1', M2 and M3 were found only after amplification of cDNAs derived from the dorso-medial portion of the telencephalon. Nucleotide sequence and Northern blot analyses showed that M1 and M1' were identical and that M2 and M3 were related genes. In situ hybridization revealed that M1 was expressed in a restricted portion of the hippocampal rudiment with a sharp boundary. M2 and M3 were expressed in the hippocampal rudiment with a more diffuse boundary than that of M1. Expression of M2 and M3 was also found in the most anterior part of the medial diencephalon with a caudal extension along the dorsal midline. These results suggest that at least two types of molecular specification occur in the dorso-medial telencephalon, contributing to the construction of the hippocampal elements during early stages of development.

Animals↗
PubMed1998

Afferent and efferent connections of the dorsocentral telencephalon in an electrosensory teleost, Gymnotus carapo.

Biotinylated dextran amine was injected unilaterally into dorsal regions of the telencephalon of the weakly electric fish Gymnotus carapo in order to study the afferent and efferent connections of specific dorsal regions with ventral regions of the telencephalon and with other regions of the central nervous system. Efferent pathways from the dorsolateral area of the telencephalon project ipsilaterally to the anterior hypothalamic nucleus, the ventral thalamus and magnocellular tegmental nucleus, whose axons reach the spinal cord. Anterograde labeling showed that the central division of the dorsal telencephalon sends efferent projections through the lateral forebrain bundle towards the ipsilateral lateral and medial preglomerular nucleus, the pretectal nucleus, the optic tectum and the dorsal torus semicircularis, regions that are all involved in the processing of electrosensory and/or multisensory information. In addition, when biotinylated dextran amine was injected into the dorsal torus semicircularis, retrogradely labeled neurons were observed in the dorsocentral area of the telencephalon. The dorsocentral area is also a target of the extra-telencephalic afferents originating from rostral, lateral and medial regions of preglomerular complex. Within the telencephalon, neurons of many ventral subdivisions project ipsilaterally to the dorsocentral area. The dorsocentral, dorsolateral and dorsomedial areas are connected ipsilaterally and reciprocally. The dorsocentral area is reciprocally connected with its contralateral homologue through the anterior commissure.

Afferent Pathways↗
PubMed2004

Misrouting of mitral cell progenitors in the Pax6/small eye rat telencephalon.

The olfactory bulb is a protruding structure formed at the rostral end of the telencephalon. Pax6-mutant mice and rats lack the olfactory bulb and, instead, develop an olfactory bulb-like structure at the lateral part of the telencephalon. Here, we report that ectopic formation of the olfactory bulb-like structure in these mutants is caused by the abnormal migration of mitral cell progenitors, which first differentiate within the olfactory bulb. Cell-tracing experiments in whole embryos in culture indicate that, in the mutants, the mitral cell progenitors that originate from the rostral part of the telencephalon migrate caudally toward the lateral part of the telencephalon. Cell transplantation demonstrates that the abnormal cell migration is not autonomous to the mitral cell progenitors themselves. The mislocation of the olfactory bulb in the mutant is not caused by loss of olfactory nerve innervation. Furthermore, transfection of a Pax6-expression vector to the mutant telencephalon restores the normal migration of mitral cell progenitors. These results provide evidence that Pax6 is required to position the mitral cell progenitors at the rostral end of the telencephalon.

Animals↗
PubMed2006

Genetic patterning of the mammalian telencephalon by morphogenetic molecules and transcription factors.

Patterning centers that produce gradients of morphogenetic molecules, including fibroblast growth factor (FGF), bone morphogenetic proteins (BMP), Wnt, Sonic hedgehog (Shh), and retinoic acid (RA), are located in telencephalic anlage during early stages of development. Genetic evidence based on loss-of-function and gain-of-function studies indicate that they are involved in regional specification of the dorsal, ventral, and lateral telencephalon. For patterning of the dorsal telencephalon, FGF8 controls the anteroposterior patterning, while BMP and Wnt molecules regulate the mediolateral patterning. Shh and retinoic acid regulate patterning of the ventral and the lateral telencephalon. The regionalization of telencephalon is accompanied by expression of region-specific codes of transcription factors, which in turn regulate different phases of neuronal development to generate different cell types in each brain region. Therefore, bioactive signals of morphogenetic molecules are translated into transcription factor codes for regional specification, which subsequently leads to neurogenesis of the diversity of cell types in different regions of the telencephalon.

Animals↗
PubMed1987

An immunohistochemical study of the telencephalon of the African lungfish, Protopterus annectens.

The telencephalon of the African lungfish, Protopterus annectens, was studied by immunohistochemical techniques in order to identify the major subdivisions of the telencephalon and determine the possible homologues of these subdivisions, if any, in other vertebrates. The distributions of four different neuropeptides (substance P, leucine-enkephalin, avian pancreatic polypeptide, and LANT6), a neurotransmitter (serotonin), and a neurotransmitter-related enzyme that is involved in catecholamine synthesis (tyrosine hydroxylase) were examined. The resultant labeling patterns indicated that the telencephalon of lungfish consists of three major subdivisions--a rostrally and dorsally situated olfactory bulb, a dorsally situated pallial region located caudal to the olfactory bulbs, and a ventrally situated subpallial regions. The dorsal and lateral pallial regions, which both receive secondary olfactory input, are somewhat distinct from one another cytoarchitectonically, but their immunohistochemical labeling characteristics did not differ. Thus, the lateral pallium and the dorsal pallium together appear to constitute an olfactory pallium in lungfishes. The medial pallium was found to consist of three immunohistochemically distinct subdivisions--a dorsal cell group, an intermediate cell group, and a ventral cell group. These medial pallial fields extend throughout the entire rostrocaudal extent of the medial wall of the telencephalon. Although one or more of these medial pallial cell groups may be homologous to specific portions of the medial pallium in land vertebrates, no specific similarities were observed to support any proposed one-to-one correspondences. The possibility that one or more of the medial pallial cell groups of lungfishes correspond to cell groups located in the dorsal pallium of land vertebrates could not be excluded. The subpallium is divided into lateral, medial, and caudal subdivisions. The lateral subdivision appears to be homologous to the basal ganglia of land vertebrates since it contains neuropeptide/neurotransmitter-specific neuronal populations that are characteristic of the striatal and pallidal portions of the basal ganglia of amniotes. The medial subdivision of the subpallium shows the topographic and immunohistochemical characteristics of the septal region and the nucleus accumbens region of the amniote telencephalon. The caudal subpallium does not show any distinctive immunohistochemical labeling characteristics and its possible homologue in land vertebrates is unclear.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1984

Cholinergic systems in the rat brain: I. projections to the limbic telencephalon.

The cholinergic projections to the limbic telecephalon in the rat were investigated by use of fluorescent tracer histology in combination with choline-O-acetyltransferase (ChAT) immunohistochemistry and acetylcholinesterase (AChE) histochemistry (pharmacohistochemical regimen). Propidium iodide or Evans Blue was infused into the olfactory bulb, hippocampus, dorsal retrohippocampal region, amygdala, and the entorhinal, perirhinal, pyriform, insular, and cingular cortices. Retrogradely transported fluorescent labels and ChAT and/or AChE were microscopically analyzed on the same brain section. Virtually all of the cholinergic projections to the limbic telencephalon derived from the basal forebrain cholinergic system composed of neurons associated with the medial septal nucleus, nuclei of the vertical and horizontal limbs of the diagonal band, the magnocellular preoptic area, the subpallidal substantia innominata and its rostral extension into the regions of the ventral pallidum laterally and the lateral preoptic area medially, and the nucleus basalis. The cingulate cortex received a small cholinergic projection from the dorsolateral tegmental nucleus in the brainstem. All of the presumed cholinergic innervation of the olfactory bulb, hippocampus, and dorsal retrohippocampal area and the majority of cholinergic afferents to posterior cingulate and entorhinal cortices derived from the medial septal nucleus, vertical and horizontal limbs of the diagonal band, magnocellular preoptic area, and rostral substantia innominata. Putative cholinergic afferents to the amygdala and to pyriform, insular, perirhinal, and anterior cingulate cortices orginated from ChAT-positive cells concentrated more caudally in the basal forebrain cholinergic system. Within the basal forebrain, no simple topographic pattern emerged to explain the cholinergic innervation of the limbic telencephalon, although an essentially reverse rostrocaudal organization was observed for afferents to the cingular region. It was noted, however, that most regions of the limbic telencephalon received cholinergic input from rostral portions of the basal forebrain cholinergic system, an observation inviting speculation that anterior aspects of the basal forebrain provide cholinergic afferents primarily to limbic structures in the telencephalon whereas more caudal portions are the source of cholinergic fibers preferentially innervating non-limbic regions. Of the total number of projection neurons innervating a given region of the limbic telencephalon, a greater proportion was ChAT-positive if phylogenetically newer target structures were innervated.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗
PubMed2005

Foxg1 is required for specification of ventral telencephalon and region-specific regulation of dorsal telencephalic precursor proliferation and apoptosis.

Null mutation of the Foxg1 gene causes hypoplasia of the mouse telencephalon and loss of ventral telencephalic structures. We show that a crucial early requirement for Foxg1 is in the induction of ventral cell fate in the telencephalon. To study later proliferative defects, we have adapted an iododeoxyuridine and bromodeoxyuridine double labeling protocol for use in the developing embryo, which allows estimation of cell cycle kinetics in a single specimen. This technique is used to demonstrate that the cell cycle is prematurely lengthened in the Foxg1-null telencephalon. These defects are first apparent at embryonic day 10.5 (E10.5) and are most severe in the rostral telencephalon. We show that apoptosis is also reduced in the same rostral domain. These defects correspond temporally and spatially with a dramatic reduction in expression of the potent signaling molecule Fgf8. We also show that in the absence of Foxg1 an excess of neurons is produced from E11.5, depleting the progenitor pool and limiting the growth of the Foxg1(-/-) telencephalon. The increase in neurogenic division coincides with an increase in BMP signaling, as detected by immunohistochemistry for phosphorylated smad-1, -5, and -8. This study reinforces Foxg1's position as a major regulator of telencephalic neurogenesis and supports the idea that Foxg1 controls precursor proliferation via regulation of Fgf signaling and differentiation via regulation of Bmp signaling.

Animals↗
PubMed2002

A direct projection from the cerebellum to the telencephalon in the goldfish, Carassius auratus.

Recent studies showed that the cerebellum is involved in cognitive functions previously thought to be located in the telencephalon only. Various indirect connections between telencephalon and cerebellum are long known and may be the basis for the interaction of these two brain areas. By means of biotinylated dextran amine injections into the telencephalon and cerebellum in the goldfish, Carassius auratus, we found a direct projection from the valvula cerebelli to the telencephalon. Together with other studies in fish, birds, and mammals, these data suggest that direct connections between cerebellum and telencephalon are more common than previously thought and may contribute to the integration of telencephalic and cerebellar functions.

Animals↗
PubMedDate not supplied

The telencephalon of the frog Xenopus based on calretinin immunostaining and gene expression patterns.

To further understand the organization and evolution of the telencephalon, we analyzed in the frog Xenopus laevis the expression of the genes Distal-less-4 (Xdll-4, comparable to the mouse gene Dlx2) and GAD-67 (XGAD-67, expressed in GABAergic cells), and compared this with calretinin immunostaining and the cytoarchitecture of the telencephalon. Our results show that like in other vertebrates, the telencephalon of the frog Xenopus is divided into two major territories: a basal, subpallial region showing a high density of cells expressing Xdll-4 and XGAD-67, and a dorsal, pallial region showing only few, dispersed cells expressing these genes. The subpallial territory of the frog Xenopus includes the septum, the amphibian basal ganglia, some basal forebrain cholinergic cell groups and some amygdala nuclei. In the pallium of the frog Xenopus, medial, dorsal, lateral, and ventral parts could be distinguished, similar to those described in amniotes. In summary, the amphibian telencephalon shows a basic morphogenetic organization similar to that of amniotes, which suggests that this organization is common to the telencephalon of all tetrapods.

Animals↗
PubMed2000

Expression of Meis and Pbx genes and their protein products in the developing telencephalon: implications for regional differentiation.

The Meis and Pbx genes encode for homeodomain proteins of the TALE class and have been shown to act as co-factors for other homeodomain transcription factors (Mann and Affolter, 1998. Curr. Opin. Genet. Dev. 8, 423-429). We have studied the expression of these genes in the mouse telencephalon and found that Meis1 and Meis2 display region-specific patterns of expression from embryonic day (E)10.5 until birth, defining distinct subterritories in the developing telencephalon. The expression of the Meis genes and their proteins is highest in the subventricular zone (SVZ) and mantle regions of the ventral telencephalon. Compared to the Meis genes, Pbx genes show a broader expression within the telencephalon. However, as is the case in Drosophila (Rieckhof et al., 1997. Cell 91, 171-183; Kurrant et al., 1998. Development 125, 1037-1048; Pai et al., 1998. Genes Dev. 12, 435-446), nuclear localized PBX proteins were found to correlate highly with Meis expression. In addition, DLX proteins co-localize with nuclear PBX in distinct regions of the ventral telencephalon.

Animals↗
PubMed1996

In vivo and in vitro evidence for the biosynthesis of testosterone in the telencephalon of the female frog.

Neurons and glial cells are capable of synthesizing various steroid hormones, but biosynthesis of testosterone in the CNS has never been reported. The aim of the present study was to demonstrate the synthesis of testosterone in the frog brain. The presence of 17beta-hydroxysteroid dehydrogenase (17beta-HSD)-like immunoreactivity was detected in a population of glial cells located in the telencephalon. Reversed-phase HPLC analysis of brain tissue extracts combined with radioimmunoassay detection revealed the presence of substantial amounts of testosterone and 5alpha-dihydrotestosterone (5alpha-DHT) in the telencephalon where 17beta-HSD-positive cells were visualized. In male frogs, castration totally suppressed testosterone and 5alpha-DHT in the blood and in the rhombencephalon but did not affect the concentration of these two steroids in the telencephalon. Chemical characterization of testosterone in female frog telencephalon extracts was performed by coupling HPLC analysis with gas chromatography-mass spectrometry. Using the pulse-chase technique with [3H]pregnenolone as a precursor, the formation of a series of metabolites was observed, including dehydroepiandrosterone, androstenedione, testosterone, 5alpha-DHT, and estradiol. These data demonstrate the existence of an active form of 17beta-HSD in the frog telencephalon, which is likely involved in testosterone biosynthesis within the brain.

17-Hydroxysteroid Dehydrogenases↗
PubMedDate not supplied

Vasopressin and oxytocin receptor mRNA expression during rat telencephalon development.

We investigated the developmental expression of vasopressin and oxytocin receptor and peptide mRNA using semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Southern blot hybridization. Messenger RNAs for both vasopressin receptor subtypes V(1)a and V(2)were present in the telencephalon from embryonic day 12 to day 20. Both V(1)a and V(2)receptor mRNA increased on day 13 and then remained stable from embryonic day 13 to day 20. Messenger RNA for the vasopressin peptide was also detected in the telencephalon from day 12 to day 20, indicating that vasopressin could be synthesized within the rat cerebral cortex during rat embryonic development. Oxytocin receptor mRNA expression was also present in the telencephalon, but expression levels varied considerably from day 12 to day 20. No oxytocin mRNA expression was detected during rat telencephalon development. Temporal patterns of vasopressin receptor and vasopressin peptide mRNA expression along with oxytocin receptor mRNA suggest a temporal role for vasopressin- and oxytocin-mediated actions during rat telencephalon development.

Animals↗
PubMed2006

A transcriptional enhancer that directs telencephalon-specific transgene expression in mouse brain.

Telencephalin (TLCN, intercellular adhesion molecule-5 [ICAM-5]) is a cell adhesion molecule belonging to the immunoglobulin superfamily, which plays important roles in dendritic morphogenesis and synaptic plasticity. The expression of TLCN is restricted to neurons in the most rostral brain segment, telencephalon. Here, we examined a transcriptional regulatory mechanism underlying the telencephalon-specific expression of TLCN. TLCN gene is located in the ICAM gene cluster containing ICAM-1, ICAM-4, and TLCN (ICAM-5) within 30 kb on the mouse chromosome 9. The nucleotide sequence of the 5'-flanking region of mouse TLCN gene is highly homologous to that of human and dog orthologs, suggesting the presence of important regulatory elements for its transcription. To determine the telencephalon-specific enhancer region, we generated several lines of transgenic mice that harbor transgenes consisting of different length of the 5'-flanking region of mouse TLCN gene (3.9, 1.5, 1.1, and 0.2 kb) fused to humanized renilla green fluorescent protein cDNA as a fluorescent reporter. Consequently, we identified a crucial region between 1.1 and 0.2 kb upstream of the transcription start site that directs the telencephalon-specific expression. This enhancer was applied to the Cre/loxP-mediated conditional expression system to generate several transgenic lines with different patterns of recombination in the telencephalon and will be further used as a powerful tool for genetic manipulation in the telencephalic neurons.

5' Flanking Region↗
PubMed1997

The forebrain of the blind cave fish Astyanax hubbsi (Characidae). I. General anatomy of the telencephalon.

This paper presents a survey of the cell groups in the telencephalon of the teleost Astyanax hubbsi, based on series of transverse sections stained with the Nissl-Klüver-Barrera and Bodian procedures. The work was conducted for two reasons. Firstly, it was intended to determine the contribution of the forebrain of blind cave fish to certain forms of behavior. An understanding of the anatomy of the telencephalic organization is essential for such a neuroethological approach. The second purpose was to provide the cytoarchitectural basis for the experimental analysis of the fiber connectivity of the telencephalon of A. hubbsi. Furthermore, information about the forebrain of characids is widely lacking, and this study may thus provide important knowledge about the cellular organization of characid forebrains for comparative anatomists. The brain of A. hubbsi is slender and elongated. Both optic nerves and optic tectum are reduced. Three longitudinal sulci-s. ypsiliformis, s. externus and s. limitans telencephali-can be distinguished in the telencephalon. A fiber lamina reaching from the s. externus to the s. limitans telencephali separates the area dorsalis (D) from the area ventralis telencephali (V). The two hemispheres are connected by fibers decussating in the anterior commissure. Although cross sections revealed no distinct fiber laminae between cytoarchitectonic components, 17 cell masses could be delineated: ten of these belong to D, seven to V. The topological analysis yielded the following results. The dorsal telencephalon D consists of three longitudinal columns, termed pars medialis (Dm), pars dorsalis and centralis (Dd and Dc) considered together, and par lateralis (Dl), which converge into a uniform posterior part (Dp). The columns can be divided into several subregions: Dm1 and Dm2, as well as Dlv and Dld, precommissurally, Dm3 and Dm4 postcommisurally. At polus posterior levels nucleus tenia can be identified. The ventral telencephalon (V) is arranged precommissurally in a periventricular neuronal column consisting of a dorsal (Vd) and ventral (Vv) part. Additionally, a lateral part (VI) is delineated. More caudally, a supracommissural part (Vs), a commissural part (Vc), a posterior part (Vp), and nucleus entopeduncularis are identified. This topological organization reflects many features characteristic for actinopterygian forebrains.

Animals↗
PubMed1999

Gli3 is required for Emx gene expression during dorsal telencephalon development.

Dentate gyrus and hippocampus as centers for spatial learning, memory and emotional behaviour have been the focus of much interest in recent years. The molecular information on its development, however, has been relatively poor. To date, only Emx genes were known to be required for dorsal telencephalon development. Here, we report on forebrain development in the extra toes (Xt(J)) mouse mutant which carries a null mutation of the Gli3 gene. This defect leads to a failure to establish the dorsal di-telencephalic junction and finally results in a severe size reduction of the neocortex. In addition, Xt(J)/Xt(J) mice show absence of the hippocampus (Ammon's horn plus dentate gyrus) and the choroid plexus in the lateral ventricle. The medial wall of the telencephalon, which gives rise to these structures, fails to invaginate during embryonic development. On a molecular level, disruption of dorsal telencephalon development in Xt(J)/Xt(J) embryos correlates with a loss of Emx1 and Emx2 expression. Furthermore, the expression of Fgf8 and Bmp4 in the dorsal midline of the telencephalon is altered. However, expression of Shh, which is negatively regulated by Gli3 in the spinal cord, is not affected in the Xt(J)/Xt(J) forebrain. This study therefore implicates Gli3 as a key regulator for the development of the dorsal telencephalon and implies Gli3 to be upstream of Emx genes in a genetic cascade controlling dorsal telencephalic development.

Animals↗
PubMed2002

Patterning of the basal telencephalon and hypothalamus is essential for guidance of cortical projections.

We have investigated the mechanisms that control the guidance of corticofugal projections as they extend along different subdivisions of the forebrain. To this aim, we analyzed the development of cortical projections in mice that lack Nkx2-1, a homeobox gene whose expression is restricted to two domains within the forebrain: the basal telencephalon and the hypothalamus. Molecular respecification of the basal telencephalon and hypothalamus in Nkx2-1-deficient mice causes a severe defect in the guidance of layer 5 cortical projections and ascending fibers of the cerebral peduncle. These axon tracts take an abnormal path when coursing through both the basal telencephalon and hypothalamus. By contrast, loss of Nkx2-1 function does not impair guidance of corticothalamic or thalamocortical axons. In vitro experiments demonstrate that the basal telencephalon and the hypothalamus contain an activity that repels the growth of cortical axons, suggesting that loss of this activity is the cause of the defects observed in Nkx2-1 mutants. Furthermore, analysis of the expression of candidate molecules in the basal telencephalon and hypothalamus of Nkx2-1 mutants suggests that Slit2 contributes to this activity.

Animals↗
PubMed1977

[The activities of the transmitter metabolizing enzymes monoamineoxidase and acetylcholinesterase and of succinic dehydrogenase were investigated in the telencephalon of Salmo irideus (teleostei) (author's transl)].

The activities of the transmitter metabolizing enzymes monoamineoxidase and acetylcholinesterase and of succinic dehydrogenase were investigated in the telencephalon of Salmo irideus (teleostei). There is a high reaction intensity of the MAO in the whole telencephalon with graded differences between the various nuclear areas. It is highest in the area dorsalis telencephali; the larger fiber tracts (Tr. olfactorius medialis et lateralis; medial and lateral forebrain bundle) are strong MAO-positive, too. There is an extremely weak AchE-reaction throughout the telencephalon. The only nuclear area which is clearly histochemically demonstrable is the regio Dm2 in the area dorsalis telencephali. The SDH-activity is demonstrable in the whole telencephalon. The activity is higher in the area dorsalis as compared with the area ventralis telencephali. In the ependym there are only a few traces of MAO- and SDH-reaction products. The recent findings may support, from a histochemical view, the hypothesis that the telencephalon of Salmo irideus represents brain structures which show structural and functional similarities with limbic telencephalic structures of higher vertebrates.

Acetylcholinesterase↗