Disease relevance of Aplysia

• Here we confirm the blocking effects of IAP and GTP gamma S (a nonhydrolysable analogue of GTP) on the ACh-induced K+-current recorded from the ganglion cells of the sea slug Aplysia and compare their effects on histamine (HA)-induced and dopamine (DA)-induced K+-currents [1].
• We expressed the Aplysia californica rho gene in Escherichia coli and purified its p21 protein to more than 90% purity [2].
• Subsequently, olomoucine was found to inhibit RNA synthesis in the eye of Aplysia and Bulla [3].
• A pertussis toxin-sensitive 8-lipoxygenase pathway is activated by a nicotinic acetylcholine receptor in aplysia neurons [4].
• Serotonin [5-hydroxytryptamine (5-HT)] enhances acetyl choline (ACh)-elicited contractures of Aplysia buccal muscles E1 and I5 . The possible role of external calcium in regulating the magnitude of ACh contracture in the presence and absence of 5-HT was investigated [5].

Psychiatry related information on Aplysia

• Evidence from Aplysia, Drosophila, mice, and rats shows that CREB-dependent transcription is required for the cellular events underlying long-term but not short-term memory [6].
• Thus, classical conditioning in Aplysia appears to be mediated, in part, by LTP due to activation of NMDA-related receptors [7].
• Recent studies of the cellular basis of feeding behavior in the marine mollusc Aplysia have focused on a neuron, C2, that has a variety of complex properties that determine the behavioral functions of the neuron [8].
• We examined whether CCh-induced bursting is modified in ganglia taken from Aplysia that previously experienced treatments inhibiting feeding, such as satiation, head shock contingent or non-contingent with food, and training animals with an inedible food [9].
• We used the Aplysia gill withdrawal reflex model system in order to study how enflurane effected both gill withdrawal adaptive behaviors and the activity of single identified neurones which are involved with the mediation of the gill withdrawal response [10].

High impact information on Aplysia

• Aplysia CREB2 represses long-term facilitation: relief of repression converts transient facilitation into long-term functional and structural change [11].
• The cAMP-responsive element-binding protein (CREB) has been implicated in the activation of protein synthesis required for long-term facilitation, a cellular model of memory in Aplysia [12].
• We find that during this phase, the transcription factor Aplysia CCAAT enhancer-binding protein (ApC/EBP) is induced rapidly by 5-HT and by cAMP, even in the presence of protein synthesis inhibitors [13].
• The insulin receptor is a tyrosine kinase receptor that is found in mammalian brain and at high concentrations in the bag cell neurons of Aplysia [14].
• Direct modulation of Aplysia S-K+ channels by a 12-lipoxygenase metabolite of arachidonic acid [15].

Chemical compound and disease context of Aplysia

• A cellular analog of classical conditioning in Aplysia was used to determine whether this form of invertebrate learning involves N-methyl-D-aspartate (NMDA)-type LTP [7].
• Addition of serotonin to the medium bathing an Aplysia abdominal ganglion causes a change in the endogenous bursting activity of the identified neuron R15 [16].
• The Ca2+/calmodulin (CaM)-activated adenylate cyclase has been implicated as playing an important associative role in classical conditioning in both Aplysia and Drosophila [17].
• In Aplysia neural tissue, the release and metabolism of arachidonic acid are stimulated by histamine or by activation of the identified L32 nerve cell circuit of the abdominal ganglion [18].
• In the buccal ganglion of Aplysia the overloading of the cholinergic presynaptic neuron by exogenous acetylcholine (AcCho) led to an enhancement of the postsynaptic response [19].

Biological context of Aplysia

• FMRFamide reverses protein phosphorylation produced by 5-HT and cAMP in Aplysia sensory neurons [20].
• Arachidonic acid, which is produced from the action of phospholipase A2 on phospholipids, is metabolized to compounds which may act as second messengers regulating ion channels in Aplysia [21].
• In the mollusk Aplysia the neurotransmitter serotonin (5HT) has a fundamental modulatory role in several forms of learning and memory that involve an increase in the efficacy of synaptic transmission between tail sensory neurons (SNs) and motor neurons [22].
• Forskolin, a highly specific activator of adenylate cyclase, produced both delay and advance phase shifts of the circadian rhythm recorded from the isolated eye of the marine mollusk Aplysia [23].
• A group of cell surface proteins, designated Aplysia cell adhesion molecules (apCAM's) was down-regulated in the sensory neurons in response to serotonin [24].

Anatomical context of Aplysia

• Here we describe a ubiquitous rat protein-endoplasmic reticulum (ER) and Golgi 30-kD protein (ERG30)-which shares structural characteristics with VAP-33, a 33-kD protein from Aplysia californica which was shown to interact with the synaptic protein VAMP [25].
• Also, 5,7-DHT reduced 5-HT-dependent, but not dopamine-dependent, histofluorescence in Aplysia central ganglia [26].
• Growth cones of Aplysia californica neurons were observed with video-enhanced contrast-differential interference contrast (VEC-DIC) microscopy as they turned at a border between poly-L-lysine-treated and untreated glass [27].
• Cyclic AMP induces changes in distribution and transport of organelles within growth cones of Aplysia bag cell neurons [28].
• Leucine aminopeptidase-like activity in Aplysia hemolymph rapidly degrades biologically active alpha-bag cell peptide fragments [29].

Associations of Aplysia with chemical compounds

• Voltage sensitivity of acetylcholine currents in Aplysia neurones in the presence of curare [30].
• Serotonin and cyclic AMP close single K+ channels in Aplysia sensory neurones [31].
• H1 and H2 histamine receptors on Aplysia neurones [32].
• Activity of an individual serotonergic neurone in Aplysia enhances synthesis of cyclic adenosine monophosphate [33].
• However, we report here that after inhibiting AChE in a cholinergic synapse in Aplysia, we found an increase not only in postsynaptic responses to presynaptic stimulation and to ionophoretic application of ACh on postsynaptic receptors, but also to ionophoretic application of carbachol [34].

Gene context of Aplysia

• Similarities in amino acid sequences of Aplysia ADP-ribosyl cyclase and human lymphocyte antigen CD38 [35].
• A human Ro/SS-A autoantigen is the homologue of calreticulin and is highly homologous with onchocercal RAL-1 antigen and an aplysia "memory molecule" [36].
• The yeast genes RHO1 and RHO2 are 70% and 57% identical, respectively, to the rho gene of the marine snail Aplysia, and they are 53% identical to each other [37].
• Two alternative conformations of the Arg84(E10) guanidium group were observed, suggesting that it participates in ligand binding to Cgb, as is the case for Arg(E10) of Aplysia Mb and Lys(E10) of Ngb [38].
• Furthermore, in transgenic Arabidopsis plants, induced expression of the Aplysia ADPR cyclase gene resulted in an increase in ADPR cyclase activity and cADPR levels, as well as elevated expression of ABA-responsive genes KIN2, RD22, RD29a, and COR47 (although to a lesser extent than after ABA induction) [39].

Analytical, diagnostic and therapeutic context of Aplysia

• The effects of ethanol (EtOH) on the early potassium current, IA, were examined in 3 identified neurons of Aplysia using voltage-clamp techniques [40].
• Using the techniques of differential display reverse transcription PCR (DDRT-PCR) and ribonuclease protection assays (RPA), we identified a cDNA whose mRNA level was increased significantly in sensory neurons by treatments of isolated pleural-pedal ganglia with serotonin for 1.5 hr or by long-term behavioral training of Aplysia [41].
• We generated an acetylcholine-binding protein from Aplysia californica by synthesis of a cDNA found in existing data bases and its expression in mammalian cell culture [42].
• Two novel serotonin catabolites, serotonin-O-sulfate and gamma-glu-serotonin-O-sulfate, are chemically characterized using capillary electrophoresis with wavelength-resolved fluorescence detection and electrospray mass spectrometry, and the formation of gamma-glu-serotonin in Aplysia californica is confirmed [43].
• IgGs purified from one antiserum, which bind specifically to rat brain VAMP, also specifically recognize proteins from Aplysia californica in immunoblotting [44].

References