Kenyon cell

In arthropods' nervous system, Kenyon cells are mushroom body neurons derived from globuli cells. Some species possess hundreds of thousands of Kenyon cells. The cells are subdivided into subtypes; for example, those that have their cell bodies outside of the calyx cup are called clawed Kenyon cells.[1] Kenyon cells were first described by F. C. Kenyon in 1896.[2] Plastic changes at the presynaptic sites of the mushroom body principal neurons called Kenyon Cells are considered to represent a neuronal substrate underlying olfactory learning and memory. It is generally believed that presynaptic and postsynaptic sites of Kenyon Cells are spatially segregated. In the mushroom body calyx, Kenyon cells receive olfactory input from projection neurons (PNs) on their dendrites. Their presynaptic sites, however, are thought to be restricted to the axonal projections within the mushroom body lobes. Kenyon Cells also form presynapses along their calycal dendrites. The mushroom bodies in insects are a paired structure that are critical for higher-order functions. In Drosophila, they are made up of ∼2500 intrinsic neurons (also called Kenyon cells) per hemisphere (there are about 200,000 neurons in the fly brain) (Heisenberg and Gerber, 2008). The dendrites of the Kenyon cells are organized into a structure called the mushroom body calyx, where some projection neurons from the antennal lobe provide olfactory information. The Kenyon cell axons course forward in a structure termed the peduncle to the anterior brain, where some of these neurons bifurcate medially and vertically, forming the medial and vertical lobes. The mushroom body lobes are further characterized into α/β, α′/β′, and γ regions (Figure 1). Moreover, the mushroom body lobes receive input from extrinsic neuromodulator neurons (e.g., dopamine and octopamine). The distinction between different lobe systems and the extrinsic input to the lobes is important for the study of PKA signaling (Gervasi et al., 2010). Kenyon cells encode information about odors by their sparse responses (identities of the responding neurons) as well as the timing of their spikes. [3]


References

  1. ↑ Strausfeld NJ (August 2002). "Organization of the honey bee mushroom body: representation of the calyx within the vertical and gamma lobes". J. Comp. Neurol. 450 (1): 4–33. doi:10.1002/cne.10285. PMID 12124764.
  2. ↑ Kenyon FC (1896). "The brain of the bee. A preliminary contribution to the morphology of the nervous system of the Arthropoda". J. Comp. Neurol. 6: 133–210. doi:10.1002/cne.910060302.
  3. ↑ Gupta, N; Stopfer, M (6 October 2014). "A temporal channel for information in sparse sensory coding.". Current Biology 24 (19): 2247–56. doi:10.1016/j.cub.2014.08.021. PMID 25264257.

External links

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