Functional analysis of a higher olfactory center, the lateral horn

By Nitin Gupta, Mark Stopfer. 2012

92 citations recorded by the source corpus.

The lateral horn (LH) of the insect brain is thought to play several important roles in olfaction, including maintaining the sparseness of responses to odors by means of feedforward inhibition, and encoding preferences for innately meaningful odors. Yet relatively little is known of the structure and function of LH neurons (LHNs), making it difficult to evaluate these ideas. Here we surveyed >250 LHNs in locusts using intracellular recordings to characterize their responses to sensory stimuli, dye-fills to characterize their morphologies, and immunostaining to characterize their neurotransmitters. We found a great diversity of LHNs, suggesting this area may play multiple roles. Yet, surprisingly, we found no evidence to support a role for these neurons in the feedforward inhibition proposed to mediate olfactory response sparsening; instead, it appears that another mechanism, feedback inhibition from the giant GABAergic neuron, serves this function. Further, all LHNs we observed responded to all odors we tested, making it unlikely these LHNs serve as labeled lines mediating specific behavioral responses to specific odors. Our results rather point to three other possible roles of LHNs: extracting general stimulus features such as odor intensity; mediating bilateral integration of sensory information; and integrating multimodal sensory stimuli.

Subfields: Cellular and Molecular Neuroscience, Genetics, Insect Science

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cellular and Molecular Neuroscience

In Genetics

In Insect Science

Citations in the corpus

Re-evaluating circuit mechanisms underlying pattern separation (2019, positive): “Feedback inhibition adaptively regulates excitability (Hamann et al., 2002; Papadopoulou et al., 2011; Gupta and Stopfer 2012; Lin et al., 2014; Temprana et al., 2014; Kee et al., 2015), in part by matching spike threshold to the overall activity level (Mitchell and Silver, 2003; Billings et al.”
Oscillatory integration windows in neurons (2016, background): “, 2002), but recent work has shown that the inhibition originates mostly from the unique feedback neuron GGN (Papadopoulou et al., 2011; Gupta and Stopfer, 2012; Lin et al., 2014).”
Odor Discrimination in Drosophila: From Neural Population Codes to Behavior (2013, background): “, 2012), it remains unresolved whether innate odor responses in general reflect the activation of labeled lines that trigger hardwired behaviors (Gupta and Stopfer, 2012; Jefferis et al., 2007; Knaden et al., 2012; Semmelhack andWang, 2009).”
Feed-Forward versus Feedback Inhibition in a Basic Olfactory Circuit (2015, methodology): “Anatomical evidence suggests that GGN inhibits both the KCs in the mushroom body (MB) and the LHNs in the lateral horn (LH), yet KCs fire sparsely while LHNs respond to odors with dense spiking [9, 12].”