The entorhinal cortex of the Megachiroptera: a comparative study of Wahlberg's epauletted fruit bat and the straw-coloured fruit bat.
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.
Gatome
Catherine W
CW
Institute of Anatomy, University of Zurich, Zurich, Switzerland.
Slomianka
Lutz
L
Mwangi
Dieter K
DK
Lipp
Hans-Peter
HP
Amrein
Irmgard
I
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
D016900:Neurofilament Proteins; D010320:Parvalbumins