Clusters of secretagogin-expressing neurons in the aged human olfactory tract lack terminal differentiation

Johannes Attems, Alan Alpar, Lauren Spence, Shane McParland, Mathias Heikenwalder, Mathias Uhlén, Heikki Tanila, Tomas G.M. Hökfelt, Tibor Harkany

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Expanding the repertoire of molecularly diverse neurons in the human nervous system is paramount to characterizing the neuronal networks that underpin sensory processing. Defining neuronal identities is particularly timely in the human olfactory system, whose structural differences from nonprimate macrosmatic species have recently gained momentum. Here, we identify clusters of bipolar neurons in a previously unknown outer "shell" domain of the human olfactory tract, which express secretagogin, a cytosolic Ca 2+ binding protein. These "shell" neurons are wired into the olfactory circuitry because they can receive mixed synaptic inputs. Unexpectedly, secretagogin is often coexpressed with polysialylated-neural cell adhesion molecule, β-III-tubulin, and calretinin, suggesting that these neurons represent a cell pool that might have escaped terminal differentiation into the olfactory circuitry. We hypothesized that secretagogin-containing "shell" cells may be eliminated from the olfactory axis under neurodegenerative conditions. Indeed, the density, but not the morphological or neurochemical integrity, of secretagogin-positive neurons selectively decreases in the olfactory tract in Alzheimer's disease. In conclusion, secretagogin identifies a previously undescribed cell pool whose cytoarchitectonic arrangements and synaptic connectivity are poised to modulate olfactory processing in humans.

Original languageEnglish
Pages (from-to)6259-6264
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume109
Issue number16
DOIs
Publication statusPublished - Apr 17 2012

Keywords

  • Calcium signaling
  • Neurodegeneration
  • Neurogenesis
  • Relay circuit
  • Tau

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'Clusters of secretagogin-expressing neurons in the aged human olfactory tract lack terminal differentiation'. Together they form a unique fingerprint.

  • Cite this