About a Snail, a Toad, and Rodents: Animal Models for Adaptation Research

Neural adaptation mechanisms have many similarities throughout the animal kingdom, enabling to study fundamentals of human adaptation in selected animal models with experimental approaches that are impossible to apply in man. This will be illustrated by reviewing research on three of such animal models, viz. (1) the egg-laying behavior of a snail, Lymnaea stagnalis: how one neuron type controls behavior, (2) adaptation to the ambient light condition by a toad, Xenopus laevis: how a neuroendocrine cell integrates complex external and neural inputs, and (3) stress, feeding, and depression in rodents: how a neuronal network co-ordinates different but related complex behaviors. Special attention is being paid to the actions of neurochemical messengers, such as neuropeptide Y, urocortin 1, and brain-derived neurotrophic factor. While awaiting new technological developments to study the living human brain at the cellular and molecular levels, continuing progress in the insight in the functioning of human adaptation mechanisms may be expected from neuroendocrine research using invertebrate and vertebrate animal models

Ca2+ Depletion from Granules Inhibits Exocytosis A STUDY WITH INSULIN-SECRETING CELLS

The secretory compartment is characterized by low luminal pH and high Ca2+ content. Previous studies in several cell types have shown that the size of the acidic Ca2+ pool, of which secretory granules represent a major portion, could be estimated by applying first a Ca2+ionophore followed by agents that collapse acidic pH gradients. In the present study we have employed this protocol in the insulin-secreting cell line Ins-1 to determine whether the Ca2+ trapped in the secretory granules plays a role in exocytosis. The results demonstrate that a high proportion of ionophore-mobilizable Ca2+ in Ins-1 cells resides in the acidic compartment. The latter pool, however, does not significantly contribute to the [Ca2+]i changes elicited by thapsigargin and the inositol trisphosphate-producing agonist carbachol. By monitoring membrane capacitance at the single cell level or by measuring insulin release in cell populations, we show that Ca2+ mobilization from nonacidic Ca2+ pools causes a profound and long lasting increase in depolarization-induced secretion, whereas breakdown of granule pH had no significant effect. In contrast, releasing Ca2+ from the acidic pool markedly reduces secretion. It is suggested that a high Ca2+ concentration in the secretory compartment is needed to sustain optimal exocytosis

ERK-regulated double cortin-like kinase (DCLK)-short phosphorylation and nuclear translocation stimulate POMC gene expression in endocrine melanotrope cells.

Contains fulltext : 96838.pdf (publisher's version ) (Open Access)10 p

The microtubule associated protein doublecortin-like regulates the transport of the glucocorticoid receptor in neuronal progenitor cells

Contains fulltext : 72489.pdf (publisher's version ) (Open Access

In vivo MR tracking of magnetically labeled cells: first clinical experience with dendritic cell vaccines in melanoma patients.

Contains fulltext : 48355.pdf (publisher's version ) (Closed access). p

Leptin Signaling Modulates the Activity of Urocortin 1 Neurons in the Mouse Nonpreganglionic Edinger-Westphal Nucleus

Leptin directly modulates the activity of midbrain LepRb expressing urocortin 1 neurons by recruiting JAK-STAT signaling mediated by STAT3 phosphorylation