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Affinati, A. H.

Publications and source records attributed to Affinati, A. H..

2 recordsLinked to original sources

Cross-Species Analysis Defines the Conservation of Anatomically-Segregated VMH Neuron Populations

The ventromedial hypothalamic nucleus (VMH) controls diverse behaviors and physiologic functions, suggesting the existence of multiple VMH neural subtypes with distinct functions. Combing Translating Ribosome Affinity Purification with RNA sequencing (TRAP-seq) data with snRNA-seq data, we identified 24 mouse VMH neuron clusters. Further analysis, including snRNA-seq data from macaque tissue, defined a more tractable VMH parceling scheme consisting of 6 major genetically- and anatomically-differentiated VMH neuron classes with good cross-species conservation. In addition to two major ventrolateral classes, we identified three distinct classes of dorsomedial VMH neurons. Consistent with previously-suggested unique roles for leptin receptor (Lepr)-expressing VMH neurons, Lepr expression marked a single dorsomedial class. We also identified a class of glutamatergic VMH neurons that resides in the tuberal region, anterolateral to the neuroanatomical core of the VMH. This atlas of conserved VMH neuron populations provides an unbiased starting point for the analysis of VMH circuitry and function.

neuroscience

tTARGIT AAVs: A sensitive and flexible method to manipulate intersectional neuronal populations

While Cre-dependent viral systems permit the manipulation of many neuron types, some cell populations cannot be targeted by a single DNA recombinase. Although the combined use of Flp and Cre recombinases can overcome this limitation, insufficient recombinase activity can reduce the efficacy of existing Cre+Flp-dependent viral systems. We developed a sensitive dual recombinase-activated viral approach: tTA-driven Recombinase-Guided Intersectional Targeting (tTARGIT) AAVs. tTARGIT AAVs utilize a Flp-dependent tetracycline transactivator (tTA) "Driver" AAV and a tetracycline response element (TRE)-driven, Cre-dependent "Payload" AAV to express the transgene of interest. We employed this system in Slc17a6FlpO;LeprCre mice to manipulate LepRb neurons of the ventromedial hypothalamus (VMH; LepRbVMH neurons) while omitting neighboring LepRb populations. We defined the circuitry of LepRbVMH neurons and roles for these cells in the control of food intake and energy expenditure. Thus, the tTARGIT system mediates robust recombinase-sensitive transgene expression, permitting the precise manipulation of previously intractable neural populations.

physiology