Distribution of Dip-allatostatin I-like immunoreactivity in the brain of the locustSchistocerca gregaria with detailed analysis of immunostaining in the central complex

Abstract

The distribution and morphology of neurons containing allatostatin-related substances in the brain of the locust Schistocerca gregaria was investigated using an antiserum against Diploptera punctata allatostatin I (Dip-allatostatin I, APSGAQRLYGFGL-amide). In each brain hemisphere, about 550 neurons in the midbrain and 500 neurons in the optic lobe exhibit Dip-allatostatin I-like immunoreactivity, including about eight lateral neurosecretory cells with processes to the retrocerebral complex. All major brain areas except the antennal lobe, the mushroom body, and large parts of the lamina, are innervated by Dip-allatostatin I-immunoreactive processes. Immunostaining in the central complex was studied in detail. The central complex is innervated by more than 260 Dip-allatostatin I-immunoreactive neurons belonging to six different cell types, four sets of tangential neurons and two sets of columnar neurons. These neurons give rise to intense immunostaining in the protocerebral bridge, in several layers of the upper division of the central body, and in the dorsalmost layer of the lower division of the central body. Double-label experiments show colocalization of Dip-allatostatin I- and serotonin-like immunoreactivities in one type of columnar and one type of tangential neurons of the central complex. The similar patterns of Dip-allatostatin I- and galanin message-associated peptide-like immunoreactivities result from cross-reactivity of the anti-galanin message-associated peptide antiserum with Dip-allatostatin I. The results provide further insight into the anatomical and neurochemical organization of the locust central complex and suggest a prominent neuroactive role for Dip-allatostatin I-related peptides in this brain area.

Mas‐allatotropin in the developing antennal lobe of the sphinx moth Manduca sexta: Distribution, time course, developmental regulation, and colocalization with other neuropeptides

“…As shown previously by competitive ELISA the serum cross-reacts with other members of the AST-A peptide family, all characterized by their C-terminal Y/FXFGLamide sequence (Vitzthum et al, 1996). In a noncompetitive ELISA analysis, no cross-reactivity of the antiserum was found with corazonin, crustacean cardioactive peptide, FMRFamide, leucomyosuppressin, locustatachykinin II, perisulfakinin, or proctolin (Vitzthum et al, 1996). Preadsorption of the Dip-AST7 antiserum with 100 lM synthetic Dip-AST7 (Sigma-Aldrich) for 1 h at room temperature abolished all immunostaining in M. sexta brain sections, whereas preadsorption of the antiserum with 100 lM synthetic FLRFamide, FMRFamide (both Sigma-Aldrich), or M. sexta allatotropin (Bachem) for 1 h at room temperature had no effect on immunostaining (Utz and Schachtner, 2005).…”

“…Antiserum against Dip-AST7, which is generally thought to recognize AST-A, was used at a concentration of 1:10,000 (kindly provided by Dr. H. Agricola, University of Jena, Germany; Utz and Schachtner, 2005). As shown previously by competitive ELISA the serum cross-reacts with other members of the AST-A peptide family, all characterized by their C-terminal Y/FXFGLamide sequence (Vitzthum et al, 1996). In a noncompetitive ELISA analysis, no cross-reactivity of the antiserum was found with corazonin, crustacean cardioactive peptide, FMRFamide, leucomyosuppressin, locustatachykinin II, perisulfakinin, or proctolin (Vitzthum et al, 1996).…”

In search of the sky compass in the insect brain

“…An accessory medulla is also present in the locust brain and this closely resembles the accessory medulla of the cockroach in anatomical organization, concentration of neuropeptides, and electrophysiological properties of neurons (Homberg et al 1991;Würden and Homberg 1995;Homberg and Würden 1997). Immunocytochemistry and single-cell dye fills revealed a prominent connection from the locust accessory medulla via the posterior optic tubercle to the protocerebral bridge (Homberg et al 1991;Vitzthum et al 1996;Homberg and Würden 1997). These "visual" inputs to the central complex at the level of the protocerebral bridge may actually be timing information from an internal circadian clock, which would constantly adjust directional output from the central complex with respect to time of day (Fig.…”

Polarization-Sensitive Descending Neurons in the Locust: Connecting the Brain to Thoracic Ganglia

“…The antiserum was a gift from Dr. Hans Agricola and was used at a dilution of 1:15,000. Competitive ELISA showed that the serum cross-reacts with other members of the A-type allatostatin family of peptides with a common Y/FXFGLamide C terminus (Vitzthum et al, 1996). The anti-FMRFamide antiserum (#671, used at 1:4,000) was generated against synthetic FMRFamide conjugated to thyroglobulin (Marder et al, 1987) and was generously supplied by Dr. Eve Marder (Brandeis University, Waltham, MA).…”