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Petanjek , Zdravko and Kostović, Ivica and Esclapez, Monique (2009) Primate-specific origins and migration of cortical GABAergic neurons. Frontiers in Neuroanatomy, 3 (26). Abstract Gamma-aminobutyric-acidergic (GABAergic) cells form a very heterogeneous population of neurons that play a crucial role in the coordination and integration of cortical functions. Their number and diversity increase through mammalian brain evolution. Does evolution use the same or different developmental rules to provide the increased population of cortical GABAergic neurons? In rodents, these neurons are not generated in the pallial proliferative zones as glutamatergic principal neurons. They are produced almost exclusively by the subpallial proliferative zones, the ganglionic eminence (GE) and migrate tangentially to reach their target cortical layers. The GE is organized in molecularly different subdomains that produce different subpopulations of cortical GABAergic neurons. In humans and non-human primates, in addition to the GE, cortical GABAergic neurons are also abundantly generated by the proliferative zones of the dorsal telencephalon. Neurogenesis in ventral and dorsal telencephalon occurs with distinct temporal profiles. These dorsal and ventral lineages give rise to different populations of GABAergic neurons. Early-generated GABAergic neurons originate from the GE and mostly migrate to the marginal zone and the subplate. Later-generated GABAergic neurons, originating from both proliferative sites, populate the cortical plate. Interestingly, the pool of GABAergic progenitors in dorsal telencephalon produces mainly calretinin neurons, a population known to be significantly increased and to display specific features in primates. We conclude that the development of cortical GABAergic neurons have exclusive features in primates that need to be considered in order to understand pathological mechanisms leading to some neurological and psychiatric diseases. Actions (login required) Downloads Downloads per month over past year
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Petanjek, Zdravko and Dujmović, Ana and Kostović, Ivica and Esclapez, Monique (2008) Distinct origin of GABA-ergic neurons in forebrain of man, nonhuman primates and lower mammals. Collegium antropologicum, 32 (Suppl.). pp. Abstract In this mini-review we present recent data about origin of GABA-ergic (gama-aminobutyric acid) neurons in the mammalian forebrain, including the diencephalon and telencephalon. The interest in GABA-ergic neurons, which in cerebral cortex mostly correspond to local circuit neurons (interneurons), has increased in the past decade. Many studies have shown that in lower mammals all hippocampal and almost all neo-cortical GABA-ergic neurons are born in the specific region named ganglionic eminence, and not locally in proliferative layers all around telencephalic vesicle. The ganglionic eminence, that represents a region with thick proliferative-subventricular layer in the ventral (basal) part of telencephalon, was classically thought to give neurons to basal ganglia and septal nuclei, whereas proliferative layers of dorsal telencephalon give neurons to cerebral cortex including hippocampus. It was thought that neurons migrate from proliferative layer to their target region following a radial orientation. However, data in lower mammals showed that this is the case only for glutamatergic principal cells, i.e. projection neurons. GABA-ergic neurons use long distance tangentional migration, parallel to pial surface to reach, from ganglionic eminence, their targeting layer in the cerebral cortex. Especially intriguing, but frequently neglecting, several studies suggest that mammalian evolution might use different developmental rules to provide GABA-ergic neurons to an expending brain. In this review we focus on specific events underlying GABA-ergic neuron development in human and non-human primates. Disturbances of the GABAergic network are found in many neurological and psychiatric disorders, some of them might result from altered production or migration of these neurons during development. Therefore, it is crucial to understand human-specific mechanisms that regulate the development of GABA-ergic neurons. Abstract in Croatian U ovom osvrtu pružamo pregled novih spoznaja o porijeklu inhibicijskih neurona koji sintetiziraju GABA (gamaamino- maslačnu kiselinu) u prednjem mozgu (prozencefalon) sisavaca, što uključuje kranji mozak (telencefalon) i me- đumozak (diencefalon). Zanimanje za GABA-ergičke neurone, koji u kori velikog mozga (korteksu) uglavnom odgovaraju neuronima lokalnih krugova (interneuronima), značajno je poraslo u proteklom desetljeću. Kao posljedica toga, potpuno se promijenilo prijašnje vjerovanje, te su novi rezultati pokazali da se u nižih sisavaca svi hipokampalni i gotovo svi kortikalni GABA-ergički neuroni rađaju u specifičnom području, tzv. ganglijski brežuljak, a ne lokalno u proliferativnim slojevima uzduž cijele ventrikularne stijenke telencefalona. Ganglijski brežuljak, koji je zapravo područje ventralnog (bazalnog) telencefalona gdje je izrazito zadebljan proliferativni-subventrikularni sloj, smatrao se izvorom neurona bazalnih ganglija i septalnih jezgara, dok su se proliferativni slojevi dorzalnog telencefalona smatrali izvorom svih kortikalnih i hipokampalnih neurona. Također se smatralo da se neuroni kreću od proliferativnih slojeva do svog konačnog odredišta prvenstveno mehanizmima radijalne migracije, ali su novi podaci pokazali da je to slučaj samo za projekcijske glutamatergičke neurone. GABA-ergički neuroni koriste mehanizam tangencijalne migracije, prelazeći velike udaljenosti od ganglijskog brežuljka do svih dijelova kore velikoga mozga krećući se paralelno s pijalnom površinom. Posebno intrigantni, ali uglavnom zanemareni, su podaci o razlikama u porijeklu GABA-ergičkih neurona koje se javljaju tijekom evolucije u sisavaca. U ovom radu posebno smo se usredotočili na specifična događanja tijekom razvoja GABA-ergičkih neurona majmuna i čovjeka. U većini neuroloških i psihijatrijskih bolesti dolazi do odstupanja unutar GABA-ergičke mreže neurona, prvenstveno kao posljedica poremećenog razvoja. Zbog toga je za razumijevanje neurobiologije ovih poremećaja potrebno istražiti mehanizme specifične čovjeku koji reguliraju razvoj različitih podvrsta GABA-ergičkih interneurona. Actions (login required) Downloads Downloads per month over past year