title: The entorhinal cortex of the Megachiroptera: a comparative study of Wahlberg's epauletted fruit bat and the straw-coloured fruit bat.
abstract: This study describes the organisation of the entorhinal cortex of the Megachiroptera, straw-coloured fruit bat and Wahlberg's epauletted fruit bat. Using Nissl and Timm stains, parvalbumin and SMI-32 immunohistochemistry, we identified five fields within the medial (MEA) and lateral (LEA) entorhinal areas. MEA fields E(CL) and E(C) are characterised by a poor differentiation between layers II and III, a distinct layer IV and broad, stratified layers V and VI. LEA fields E(I), E(R) and E(L) are distinguished by cell clusters in layer II, a clear differentiation between layers II and III, a wide columnar layer III and a broad sublayer Va. Clustering in LEA layer II was more typical of the straw-coloured fruit bat. Timm-staining was most intense in layers Ib and II across all fields and layer III of field E(R). Parvalbumin-like staining varied along a medio-lateral gradient with highest immunoreactivity in layers II and III of MEA and more lateral fields of LEA. Sparse SMI-32-like immunoreactivity was seen only in Wahlberg's epauletted fruit bat. Of the neurons in MEA layer II, ovoid stellate cells account for approximately 38%, polygonal stellate cells for approximately 8%, pyramidal cells for approximately 18%, oblique pyramidal cells for approximately 6% and other neurons of variable morphology for approximately 29%. Differences between bats and other species in cellular make-up and cytoarchitecture of layer II may relate to their three-dimensional habitat. Cytoarchitecture of layer V in conjunction with high encephalisation and structural changes in the hippocampus suggest similarities in efferent hippocampal --> entorhinal --> cortical interactions between fruit bats and primates.
authors.affiliation: Institute of Anatomy, University of Zurich, Zurich, Switzerland.
authors.forename: Catherine W
authors.initials: CW
authors.lastname: Gatome
authors.forename: Lutz
authors.initials: L
authors.lastname: Slomianka
authors.forename: Dieter K
authors.initials: DK
authors.lastname: Mwangi
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Lipp
authors.forename: Irmgard
authors.initials: I
authors.lastname: Amrein
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000033:anatomy & histology* / Q000145:classification*; D018728:Entorhinal Cortex / Q000033:anatomy & histology* / Q000166:cytology / Q000378:metabolism; D005260:Female; D021621:Imaging, Three-Dimensional; D016900:Neurofilament Proteins / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010320:Parvalbumins / Q000378:metabolism; D013238:Stereotaxic Techniques
chemical_list: D016900:Neurofilament Proteins; D010320:Parvalbumins