Primárna senzorická kôra mikroftalmických cicavcov, prispôsobenie na habitat a spôsob života

Abstract

Mikroftalmia sa v priebehu evolie vyvinula u nepruznch druhov cicavcov niekoľkokr nezisle na sebe (napr. u hlodavcov, echolokujich netopierov, piskorov). Vzhľadom k tak rozsiahlej konvergentnej evolii, štium cicavcov s redukovanmi očami poskytuje jedinečn prtup k chaniu adaptneho vznamu zmyslovej regresie a vplyvu perifnej redukcie na organiziu centrnych štrukt a kros modnu reorganiziu alebo kompenziu. V tejto pri som zhrnula naše sčsn znalosti o primnej senzorickej ke mikroftalmickch cicavcov. U podzemnch druhov (krt vchodoamerick, Scalopus aquaticus; krt hviezdonos, Condylura cristata; slepec egyptsk, Spalax ehrenbergi; rypoš lys, Heterocephalus glaber) je zreteľn expanzia somatosenzorickej ky, ktor spracova hmatov podnety. Hmat u nich hr veľmi dežit ohu pri orientii v podzemnch trojdimenzionnych tuneloch, ktor sa dynamicky menia. Mikroftalmick echolokuje netopiere, ktorch telo je prispoben letu, maj topograficky reorganizovan somatosenzorick ku, redukovan ku zrakov a zvčšn , zložito organizovan sluchov ku. Terestrick druhy piskorovitch (Soricidae, Insectivora) nemaj žiadne špecifick adpatie na ovni zmyslovej ky. Zaujav je však, že ich primna zrakov ka nie je vrazne redukovan naprik tomu, že maj veľmi redukovan oči ( 1 mm). Tieto poznatky jasne ukazuj , že organizia sentorickej ky održ druhovo špecifick...

Microphthalmia has evolved in evolution many times independently within unrelated groups of mammals (e.g., rodens, echolocating bats, shrews). Due to such extensive convergent evolution, investigation of mammals with reduced eyes provides a unique approach for understanding the adaptive significance of sensory regression, the impact of peripheral reduction on organization of central sensory structures and cross-modal reorganization or compensation. In this thesis I review our current knowledge concerning the organization of the primary sensory cortex in microphthalmic mammals. In subterranean species (the eastern mole, Scalopus aquaticus; the star-nosed mole, Condylura cristata; the blind mole rat, Spalax ehrenbergi; the naked mole rat, Heterocephalus glaber) is obvious expansion of somatosensoty cortex, which processes tactile information.The sense of touch plays a pivotal role in orientation in their dynamically changing three-dimensional burrow systems. Microphthalmic, echolocating bats whose body is adapted to flight have topographicly reorganized somatosensory cortex, reduced the visual cortex and expanded, complexly organized acoustic cortex. Terrestrial shrews (Soricidae, Insectivora) do not posses any specific adaptations at level of the sensory cortex. Interestingly, their primary visual cortex is...