Systems genetic analysis of hippocampal neuroanatomy and spatial learning in mice.

Variation in hippocampal neuroanatomy correlates well with spatial learning ability in mice. Here, we have studied both hippocampal neuroanatomy and behavior in 53 isogenic BXD recombinant strains derived from C57BL/6J and DBA/2J parents. A combination of experimental, neuroinformatic and systems genetics methods was used to test the genetic bases of variation and covariation among traits.

The neuropeptide SIFamide modulates sexual behavior in Drosophila.

The expression of Drosophila neuropeptide AYRKPPFNGSIFamide (SIFamide) was shown by both immunohistology and in situ hybridization to be restricted to only four neurons of the pars intercerebralis. The role of SIFamide in adult courtship behavior in both sexes was studied using two different approaches to perturb the function of SIFamide; targeted cell ablation and RNA interference (RNAi). Elimination of SIFamide by either of these methods results in promiscuous flies; males perform vigorous and indiscriminant courtship directed at either sex, while females appear sexually hyper-receptive.

AKH-producing neuroendocrine cell ablation decreases trehalose and induces behavioral changes in Drosophila.

Adipokinetic hormone (AKH) is a metabolic neuropeptide principally known for its mobilization of energy substrates, notably lipid and trehalose during energy-requiring activities, such as flight and locomotion. Drosophila melanogaster AKH cell localization in corpora cardiaca, as in other insect species, was confirmed by immunoreactivity and by a genetic approach using the UAS/GAL4 system. To assess AKH general physiological rules, we ablated AKH endocrine cells by specifically driving the expression of apoptosis transgenes in AKH cells.

Synchronized neural activity in the Drosophila memory centers and its modulation by amnesiac.

The mushroom bodies are key features of the brain circuitry for insect associative learning, especially when evoked by olfactory cues. Mushroom bodies are also notable for the close-packed parallel architecture of their many intrinsic neuronal elements, known as Kenyon cells. Here, we report that Kenyon cells of adult Drosophila exhibit synchronous oscillation of intracellular calcium concentration, with a mean period of approximately 4 min.

Hormonally controlled chloride movement across Drosophila tubules is via ion channels in stellate cells.

Anion conductance across the Drosophila melanogaster Malpighian (renal) tubule was investigated by a combination of physiological and transgenic techniques. Patch-clamp recordings identified clusters of 4, 4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS)-sensitive "maxi-chloride" channels in a small domain of the apical membrane. Fluid secretion assays demonstrated sensitivity to the chloride channel blockers 5-nitro-2-(3-phenylpropylamino)benzoic acid, diphenylamine-2-carboxylate, anthracene-9-carboxylic acid, and niflumic acid.