Mouse brain potassium channel beta1 subunit mRNA: cloning and distribution during development.

The pore-forming alpha subunits of voltage-gated potassium channels in neurons and other excitable cells are expressed in association with accessory beta subunits. These subunits both promote insertion of channel complexes into surface membranes and influence their electrophysiological properties. As part of an effort to understand the regulation of voltage-gated potassium channels during development, we cloned the mouse homolog of the rat Kvbeta1 potassium channel subunit.

In situ hybridization of whole-mounts of Aplysia ganglia using non-radioactive probes.

A protocol for carrying out in situ hybridization with non-radioactive, digoxigenin-labelled probes has been developed for whole-mounts of Aplysia ganglia. Whole-mount preparations preserve the anatomical relationships of neurons within intact ganglia and facilitate the precise identification of a particular neuron in live preparations so that functional studies can be correlated with biochemical attributes of an identified neuron. The protocol was developed with the use of probes to messenger RNAs that are abundant in Aplysia neurons.

Single RNA species injected in Xenopus oocyte directs the synthesis of active choline acetyltransferase.

In vitro synthesized complementary RNA (cRNA) transcribed from a non-full length Drosophila choline acetyltransferase (ChAT) cDNA clone will direct the synthesis of enzymatically active and immunologically recognizable protein when injected into Xenopus oocytes. The levels of ChAT activity expressed in injected oocytes are proportional, over 4 orders of magnitude difference, to the concentration of injected 'sense' orientation cRNA. GpppG capping of the in vitro synthesized cRNA is not necessary for expression of active ChAT but inclusion of the capping compound during in vitro transcription results in higher levels of enzyme expression at lower levels of cRNA injection.

Long-term regulation of synaptic acetylcholine release and nicotinic transmission: the role of cyclic AMP.

1. Using the rat superior cervical ganglion in vitro, the relative efficacy of nicotinic synaptic transmission was estimated by recording the postganglionic compound action potential and the amount of endogenous acetylcholine (ACh) released. These two parameters were correlated in individual ganglia by sampling the bathing medium for the assay of ACh while simultaneously recording the postganglionic response.

Development of neurotransmitter metabolism in embryos of the leech Haementeria ghilianii.

We have investigated the development of neurotransmitter metabolism in embryos of the glossiphoniid leech Haementeria ghilianii. The neurotransmitter content of dissected embryonic tissues was measured by means of radioenzymatic assays, while the presence of neurotransmitters in individual identified neurons was detected by means of immunocytochemical and monoamine histofluorescence techniques. The capacity for synthesis of neurotransmitters was measured by incubating dissected embryonic tissues in radiolabeled neurotransmitter precursors.

Long-term potentiation of synaptic acetylcholine release in the superior cervical ganglion of the rat.

The release of endogenous acetylcholine (ACh) from the in vitro rat superior cervical ganglion was measured by assaying the bathing medium. Simultaneously, synaptic transmission in the ganglion was assessed by recording post-ganglionic compound action potentials. A brief period of tetanic preganglionic stimulation (20 Hz for 20 s) induced a long-term potentiation of the post-ganglionic compound action potential.

Choline acetyltransferase and acetylcholine levels in Drosophila melanogaster: a study using two temperature-sensitive mutants.

Choline acetyltransferase (ChAT, acetyl-CoA-choline-O-acetyltransferase, EC 2.3.1.

Histaminergic synaptic transmission in the cerebral ganglion of Aplysia.

Standard intracellular stimulating and recording techniques including voltage-clamp were used to analyze the synaptic responses mediated by two identifiable histamine-containing neurons (HCNs), designated C2 neurons, located in bilaterally symmetric clusters of the isolated cerebral ganglion of Aplysia california. Activation of each C2 induced unitary chemically mediated synaptic potentials in over 15 identified ipsilateral follower neurons. Several additional followers were connected to the HCNs by nonrectifying electrical synapses.

Evidence for genetic influences on neurotransmitter content of identified neurones of Lymnaea stagnalis.

Neurotransmitter content was measured in two identified giant neurones in isogenic and wild-type populations of the freshwater pond snail Lymnaea stagnalis. The paired serotonergic cerebral giant neurones (LC1 and RC1) have higher transmitter levels and less variability in inbred animals than in wild-type animals. The transmitter content of the unpaired dopaminergic right pedal giant neurone (RPeD1) does not differ between inbred and wild-type animals in either level or variability.

5-hydroxytryptamine measurements in molluscan ganglia and neurons using a modified radioenzymatic assay.

A radioenzymatic procedure for the determination of sub-picomole amounts of 5-hydroxytryptamine (5-HT) is described. It is a modification of the method originally described by Saavedra et al. (1973), in which 5-HT was measured as the radiolabelled product [3H]5-methoxy-N- acetyltryptamine , after incubation with [3H]S-adenosylmethionine, acetyl-CoA, and the enzymes hydroxyindole-O-methyltransferase (EC 2.

Immunocytochemical localization and direct assays of serotonin-containing neurons in Aplysia.

Serotonin-containing neurons were localized in the central nervous system of Aplysia californica by the combination of an immunohistochemical procedure for wholemounts of Aplysia ganglia and, in parallel experiments, by the direct measurement of serotonin in individual neurons with a radioenzymatic assay. Paraformaldehyde fixed, desheathed ganglia were incubated in a commercially available antiserum against a conjugate of serotonin and bovine serum albumin. The bound antibody was visualized by an indirect antibody procedure using the horseradish peroxidase catalyzed reduction of the chromogen, diaminobenzidine, and a cobalt-nickel intensification procedure.

Presence of octopamine in firefly photomotor neurons.

Various tissues involved in producing luminescence in larval fireflies (Photuris versicolor) were examined for the presence of octopamine. These tissues included the terminal abdominal ganglion (A8) which innervates the paired lantern organs, the cell bodies of the photomotor neurons and the isolated larval lanterns. A previous study has identified the 4 motoneurons arising from A8 which bilaterally innervate the paired larval lanterns through symmetrical axons existing both sides of the ganglion.

On the nature of histamine-mediated slow hyperpolarizing synaptic potentials in identified molluscan neurones.

1. Standard intracellular stimulating and recording techniques were used to test the correspondence between monosynaptic post-synaptic potentials (p.s.

Embryonic development of identified neurons: temporal pattern of morphological and biochemical differentiation.

Individually identified neurons can be recognized in grasshopper embryos, and are accessible to examination by morphological, physiological, and biochemical techniques from their birth to their maturation. Only after the axon of an identified neuron reaches its postsynaptic target does the neurotransmitter accumulate, the soma rapidly enlarge, and the central arborizations greatly expand.