Reversal of age-related learning deficiency by the vertebrate PACAP and IGF-1 in a novel invertebrate model of aging: the pond snail (Lymnaea Stagnalis)

With the increase of life span, nonpathological age-related memory decline is affecting an increasing number of people. However, there is evidence that age-associated memory impairment only suspends, rather than irreversibly extinguishes, the intrinsic capacity of the aging nervous system for plasticity (1). Here, using a molluscan model system, we show that the age-related decline in memory performance can be reversed by administration of the pituitary adenylate cyclase activating polypeptide (PACAP). Our earlier findings showed that a homolog of the vertebrate PACAP38 and its receptors exist in the pond snail (Lymnaea stagnalis) brain (2), and it is both necessary and instructive for memory formation after reward conditioning in young animals (3). Here we show that exogenous PACAP38 boosts memory formation in aged Lymnaea, where endogenous PACAP38 levels are low in the brain. Treatment with insulin-like growth factor-1, which in vertebrates was shown to transactivate PACAP type I (PAC1) receptors (4) also boosts memory formation in aged pond snails. Due to the evolutionarily conserved nature of these polypeptides and their established role in memory and synaptic plasticity, there is a very high probability that they could also act as “memory rejuvenating” agents in humans

A Next Generation High-speed Data Acquisition System for Multi-channel Infrared and Optical Photometry

We report the design, operation, and performance of a next generation high-speed data acquisition system for multi-channel infrared and optical photometry based on the modern technologies of Field Programmable Gate Arrays, the Peripheral Component Interconnect bus, and the Global Positioning System. This system allows either direct recording of photon arrival times or binned photon counting with time resolution up to 1-$\mu$s precision in Universal Time, as well as real-time data monitoring and analysis. The system also allows simultaneous recording of multi-channel observations with very flexible, reconfigurable observational modes. We present successful 20-$\mu$s resolution simultaneous observations of the Crab Nebula Pulsar in the infrared (H-band) and optical (V-band) wavebands obtained with this system and 100-$\mu$s resolution V-band observations of the dwarf nova IY Uma with the 5-m Hale telescope at the Palomar Observatory.Comment: 11 pages, including 4 figures, to appear in PAS

Multifunctional Role of Pacap-Like Peptides in Molluscs

The purpose of this review is to highlight the role of pituitary adenylate cyclase-activating polypeptide (PACAP) in a range of physiological and behavioral processes of gastropod molluscs, Helix and Lymnaea. Since its discovery in 1989 PACAP has become increasingly recognized for its important and diversified roles in the central and peripheral nervous system and in several peripheral organs of a variety of vertebrate and invertebrate species. Twenty-two years after its discovery, PACAP is now one of the most extensively studied of the neuropeptides. This review surveys the importance of PACAP and PACAP-like peptides in invertebrates, focusing mainly on the gastropod molluscs. The relevance of studies on lower vertebrates and invertebrates, which do not have a pituitary gland, is to contribute to the unraveling of fundamental effects of PACAP or PACAP-like peptides and to provide a comparative view

A homolog of the vertebrate pituitary adenylate cyclase-activating polypeptide is both necessary and instructive for the rapid formation of associative memory in an invertebrate

Similar to other invertebrate and vertebrate animals, cAMP dependent signaling cascades are key components of long-term memory (LTM) formation in the snail Lymnaea stagnalis, an established experimental model for studying evolutionarily conserved molecular mechanisms of long-term associative memory. Although a great deal is already known about the signaling cascades activated by cAMP, the molecules involved in the learning-induced activation of adenylate cyclase (AC) in Lymnaea remained unknown. Using Matrix-Assisted Laser Desorption/Ionization Time-of-flight (MALDI-TOF) mass spectroscopy in combination with biochemical and immunohistochemical methods, recently we have obtained evidence for the existence of a Lymnaea homologue of the vertebrate pituitary adenylate cyclase activating polypeptide (PACAP) and for the AC activating effect of PACAP in the Lymnaea nervous system. Here we first tested the hypothesis that PACAP plays an important role in the formation of robust LTM after single-trial classical food-reward conditioning. Application of the PACAP receptor antagonist PACAP6-38 around the time of single-trial training with amyl acetate and sucrose blocked associative LTM, suggesting that in this strong food-reward conditioning paradigm the activation of AC by PACAP was necessary for LTM to form. We found that in a weak multi-trial food-reward conditioning paradigm, lip-touch paired with sucrose, memory formation was also dependent on PACAP. Significantly, systemic application of PACAP at the beginning of multi-trial tactile conditioning accelerated the formation of transcription dependent memory.Our findings provide the first evidence to show that in the same nervous system PACAP is both necessary and instructive for fast and robust memory formation after reward classical conditioning

Neuromoduláció sejtszintű mechanizmusainak vizsgálata ideg-izom és ideg-mirigy kapcsolatokban. = Cellular mechanisms of the neuromodulation in neuromuscular and neuroglandular junctions.

Az éticsiga nyálmirigy jó modell az ideg-izom, ideg-mirigy szinapszis és a szekréció molekuláris mechanizmusának a tanulmányozásában. A mirigyben négyféle sejttípust azonosítottunk és megállapítottuk, hogy azok száma, eloszlása az aktív és inaktív állatokban eltérő és az ingerületáttevődés nem-szinaptikus úton valósul meg. A varikozitásokban lévő vezikulákból dopamin, szerotonin és neuropeptidek szabadulnak fel. A mirigysejtek közötti gap-junction ill. deszmoszóma kapcsolatok biztosítják a szerv szinkron működését. Leírtuk a mirigysejtek passzív és aktív elektromos tulajdonságait, és a feszültségfüggő ion-konduktanciákat. Jellemeztük a transzmitter receptorokat, amelyek heteromér formában vannak jelen, ily módon egymás hatását antagonizálják. Eredményeink ujabb adatokkal szolgálnak a puhatestüek 5HT receptorainak osztályozásához. A transzmitterhatást számos neuropeptid modulálja, amely csak a puhatestüekben fordul elő, de a PACAP is, melynek jelenlétét és szerepét puhatestűekben kimutattuk. Egy endogén neuropeptid szignalizációs útvonalát vizsgáltuk és megállapítottuk, hogy G-protein kapcsolt és amelyben mindkét disszociált alegység részt vesz és a deszenzitizációt egy protein kináz enzim végzi. A fiziológiai ingerek hatására a cisztikus sejtek száma megnőtt, melyek kivétel nélkül a programozott sejthalál morfológiai és molekuláris jeleit mutatták. Megállapítottuk, hogy a nyálfelszabadulás fiziológiai útja a mitochondrium-kaszpáz mediált útvonal. | The snail salivary gland is a suitable model in studying neuro-muscular, neuro-glandular synapse and the molecular mechanism of salivation. For cell types were identified in the gland and it was found, that distribution and number of different cell types were different in active and inactive snails. Vesicles in varicosities liberate dopamine, serotonin and number of neuropeptides. Gap-junction and desmosome-like structures ensure the synchronization of gland cells. Passive and active electrical properties of cells were examined and voltage-dependent ion currents were characterized. It was found that receptors occur in heterometric form, they bind both DA and 5HT and thereby antagonizing its effect. Our results contribute to the characterization and classification of 5HT-receptors in mollusc. The transmitter effect is modulated by peptides present only in molluscs, and by PACAP occurrence and distribution of which is described in mollusc. Signalling pathway of the neuropeptide (MIP) was studied and found that it is G-protein coupled and both subunits are active and the desensitization of the receptor is performed by receptor kinase. Physiological stimuli such as transmitters or nerve stimulation increased the number of cystic cells. These cells every time revealed a morphological and molecular signs of the programmed cell death. It is concluded, that the mitochondrial-caspase pathway of the programmed cell death is a physiological way of the saliva release

Comparative local analysis of metabolites, lipids and proteins in intact fish tissues by LAESI mass spectrometry

Direct mass spectrometric analysis of animal tissues is an emerging field enabled by recent developments in ambient ion sources. Label-free in situ analysis of metabolites, lipids, and peptides/proteins from intact tissues in whole fish specimens of different gender and age were performed by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Hypertrophied glandular tissue (gill gland) of adult male Aphyocharax anisitsi (bloodfin tetra) was compared with gill tissues in females of the same species. Comparison of a large number of sample-specific ions was aided by a multivariate statistical method based on orthogonal projections to latent structures discriminant analysis. More than 200 different ions were detected in the mass spectra corresponding to primary metabolites, hormones, lipids and peptides/proteins. The gill tissues of the sexually mature males exhibited multiply charged ions in the 6+ to 10+ charge states corresponding to a protein with a molecular weight of 11 380 Da. This protein was present only in the mature male gill glands but absent in the corresponding area of the female and immature male specimens. An additional nine proteins were detected by LAESI-MS in both the male and female gill tissues

Inter- és intracelluláris jelátviteli mechanizmusok tér- és időbeli szerveződése gerinctelenek idegrendszerében = Spatial and temporal organization of inter- and intracellular signaling pathways in the nervous system of invertebrates

Inter- és intracelluláris hírvivő rendszerek szerveződésének kémiai-neuroanatómiai, hisztokémiai, neurokémiai és funkcionális jellemzőit vizsgáltuk az összehasonlító neurobiológia két gastropoda modellállatában (Lymnaea stagnalis, Helix pomatia). i) Azonosítottuk a vesztibuláris érzékszervben, a statocystában (Lymnaea) a szenzoros sejtek projekciós rendszerét, térbeli elrendeződésükett, kémiai hírvivőiket és szinaptikus bemeneteiket. ii) Azonosítottuk a glutamáterg rendszer központi és perifériás elemeit a felnőtt és fejlődő Lymnaea idegrendszerében, valamint a glutamát transzporterek (VGluT, EAAT) funkcionális jellemzőit, molekuláris szerkezetét és mRNS transzkripcióját. iii) Igazoltuk aminerg (szerotonin, dopamin) rendszerek meghatározó szerepét a Lymnaea egyedfejlődésének menetében és felnőttkori magatartásformáinak érésében. iv) Kimutattuk a pofaizomzatban a szerotonerg innerváció és az izomrendszer párhuzamos érését, továbbá azonosítottuk a periféria (pofa- és talpizomzat) szerotonerg szabályozásának cAMPhez kapcsolt 5HT6-receptorát, illetve az embrionális forgómozgás 5-HT1A receptorát. v) Azonosítottuk és molekuláris szinten differenciáltuk a felnőtt és fejlődő központi idegrendszer szerveződésében meghatározó szerepet játszó extracelluláris matrix komponenseket. Eredményeink hozzájárulnak a neuronális szignalizációt, illetve magatartásformákat meghatározó celluláris folyamatok, továbbá az idegi szabályozás kémiai és molekuláris eseményeinek pontosabb megismeréséhez. | Chemical-neuroanatomical, histochemical, neurochemical and functional organization of inter- and intracellular signaling systems were investigated in two model gastropod species of comparative neurobiology (Lymnaea stagnalis, Helix pomatia). i) Projection pattern, chemical heterogeneity and spatial distribution of the sensory hair cells of the vestibular organ (statocyst) of Lymnaea were identified. ii) Distribution and organization of the central and peripheral elements of the glutamatergic system in the adult and developing Lymanea were described, and the transporters (VGluT, EAAT) were cloned, in situ hybridized and functionally characterized. iii). The pivotal role of aminergic (serotonin, dopamine) systems in the embryogenesis and maturation of adult-like behaviors of Lymnaea was proven. iv) Timing and spatial organization of serotonergic innervation and buccal muscle development during Lymanea ontogenesis, as well as the serotonergic receptor cascade involved in feeding and locomotion (5-HT6-cAMP), and intracapsular rotation (5-HT1A-cAMP) was revealed. v). Extracellular matrix components playing a determining role in CNS organization and plastic events were identified and differentiated according to their molecular composition in adult and developing gastropods. The results contribute to a better understanding of neuronal signaling and regulatory processes underlying different behaviors, and to further analyze the chemical and molecular events of neuronal regulations