Apical Spike Research Articles

Regeneration pattern and genome-wide transcription profile of rhizome axillary buds after perennial rice harvest.

Perennial rice is a new type of rice that allows the harvest of rice for multiple years without growing new seedlings annually. This technology represents a green and sustainable agricultural production mode with many advantages for balancing agricultural ecology and food security. However, the differences in regeneration patterns between perennial and annual rice and the gene regulatory pathways of the apical dominance in axillary bud growth after harvest in perennial rice are still unclear. In this study, perennial rice (PR23) and annual rice (Chugeng28) were used to investigate axillary bud growth patterns before and after apical spike removal. After elimination of apical dominance at different development stages, perennial rice rhizome axillary buds at the compression nodes germinated more rapidly than others and developed into new seedlings. The axillary buds at the high-position nodes in annual rice grew faster than those at other nodes. Furthermore, the global gene expression patterns of PR23 rhizome buds at compression nodes grown for 1, 3, 4, and 5 days after apical spike removal were analyzed by transcriptome sequencing. Compared with the control buds without apical removal, 264, 3,484, 2,095, and 3,398 genes were up-regulated, and 674, 3,484, 1,594, and 1,824 genes were down-regulated in the buds grown for 1, 3, 4, and 5 days after apical spike removal, respectively. Trend analysis of the expressed genes at different time points was performed and co-expression network was constructed to identify key genes in rhizome axillary bud regrowth. The results showed that 85 hub genes involved in 12 co-regulatory networks were mainly enriched in the light system, photosynthesis-antenna protein, plant hormone signal transduction, ABC transporter and metabolic pathways, which suggested that hormone and photosynthetic signals might play important roles in the regulation of rhizome axillary bud regeneration in perennial rice. Overall, this study clarified the differences in the regeneration patterns of axillary buds between perennial and annual rice and provided insight into the complex regulatory networks during the regeneration of rhizome axillary buds in perennial rice.

Contribution of Proximal and Distal Grains Within Spikelets in Relation to Yield and Yield Components in the Winter Wheat Production Region of China From 1948 to 2012

Grain number and weight within a spikelet are major yield components which determine the grain yield in wheat. The objective of this study was to explore genetic gains in grain performance within wheat spikelets at the individual grain level and its effect on grain yield and evaluate genetic progress in stem internode length and other yield-related traits. We conducted field experiments across three growing seasons in the western Yellow and Huai Valley of China; incorporating 17 bread wheat cultivars released from 1948 to 2012. Yields were significantly correlated with year of release. Yield gains equated to 3.95 g m−2 yr−1 in response to increases in total grain weight per m2 (GW) in proximal (G1 and G2) and distal (G3 and G4) grains, despite a decline in the proportional contribution of proximal grains to yield and increase in the proportional contribution of distal grains to yield with year of release. Grain number per m2 (GN), thousand-grain weight (TGW), and harvest index (HI) increased with year of release, but plant height decreased. Both grain number per spikelet of proximal and distal grain contributed to the increase in total GN. However, the contribution ratio of GN in proximal grains to total GN declined, and the proportion in distal grains increased. Average single grain weight (SGW) increased linearly at G1, G2, G3, and G4 with year of release and contributed to the increase in TGW. The G3 and G4 grain positions had much lower individual grain weights but increased at a faster rate than G1 and G2. At G1, G2, and G3 grain positions, from bottom to top spikelets, the newly released cultivars had the heaviest grains and the old cultivars had the lightest grains. New cultivars had more spikelets than old cultivars and the number of grains (proximal and distal grains) in the apical spike increased with year of release. The length of five internodes decreased significantly with year of release, more so in the upper than lower internodes, all of which contributed to the decline in plant height. In summary, increasing the number and weight of distal grains could increase grain yield, TGW, and GN.

Predicting synchronous and asynchronous network groupings of hippocampal interneurons coupled with dendritic gap junctions

Direct electrical communication between central nervous system (CNS) neurons including those in the hippocampus is well-established. This form of communication is mediated by gap junctions and it is known that this coupling is important for brain rhythms such as gamma (20–80 Hz) which occur during active behavioural states. It is also known that gap junctions are present at several locations along the dendrites of hippocampal interneurons including parvalbumin-positive basket cell types. Weakly coupled oscillator theory, which uses phase response curves (PRCs), has been used to understand and predict the dynamics of electrically coupled networks. Here we use compartmental models of hippocampal basket cells with different levels of basal and apical spike attenuation together with the theory to show that network output can be broken down into three groupings: synchronous, asynchronous and antiphase-like patterns. Moreover, quantified PRCs can be used as a rule of thumb to determine the occurrence of a particular grouping under weak coupling conditions, which in turn implies that spike delays are critical factors in determining network output. In moving beyond weak coupling to encompass the full physiological regime of coupling strengths with network simulations, we note that it is important to be able to differentiate between these different groupings as it affects how the network responds with modulation. Specifically, an asynchronous grouping provides more dynamic richness as a larger range of phase-locked states can be expressed with strength changes. From a functional viewpoint it may be that modulation of electrically coupled networks are key to controlling cell assemblies that contribute to information coding brain substrates.

Responses and spike generation in the largest antennal taste hairs of Periplaneta brunnea Burm.

The largest taste hair type of the 20 distal antennal segments is investigated electrophysiologically. Two chemoreceptors respond to potassium chloride, tripotassium citrate but not to choline salts, another one to sucrose, but not to D-glucose and only slightly to D-fructose. No response was obtained with pure water. Spikes with a leading negative phase indicate that the primary process controls an apical spike generator localized in the membranes of the outer dendritic segment. The succeeding basal spike consists of two positive phases, that are interpreted as the result of two further spike generation zones, one at the dendritic inner segments and the other at the origin of the axon. Spike activity in the mechanoreceptor also starts with negative going spikes, that are followed by a series of solely positively going ones. TTX applied to the hair tip inhibits the apical spike generator of the chemo- and mechanoreceptor cells.

Fetal tooth development and adult replacement in Dermophis mexicanus (Amphibia: Gymnophiona): Fields versus clones

Teeth of fetuses of a caecilian, Dermophis mexicanus (Amphibia: Gymnophiona), show ontogenetic variation in crown structure from small, multidenticulate, and non-pedicellate to larger, spoon-shaped, pedicellate teeth with a single apical spike. Number of denticles decreases as enamel-secreting cells mature. Numbers of teeth and of tooth rows increase ontogenetically. A fetal vomeropalatine set of teeth is present in D. mexicanus but absent in species previously examined. Teeth transitional to the adult shape and arrangement appear shortly before birth. The transition is correlated with birth, not fetal size. There is relatively little increase in numbers of teeth during the juvenile period. The pattern of development does not fully agree with either morphogenetic field theory or with clone theory, both as defined by Osborn ('78). Sequence of initiation is appropriate to either. Tooth shape changes agree with aspects of clone theory. Multiple rows of fetal teeth and the transition to adult follow field theory. Clone theory holds that patterns of development and shape are self-regulated, field theory that they are controlled extrinsically. I suggest that substances regulating differentiation mediate early development, and hormones later development, including inception of adult teeth, and are comparable to "field substances" influencing primordia that originate according to clone theory. Components of both theories are appropriate to analyzing tooth development phenomena.

Chlorophyll-deficient mutation frequency in barley following continuous gamma irradiation over a wide range of exposures throughout the life cycle

An experiment was conducted to test the influence of continuous γ-irradiation over a wide range of exposures throughout one life cycle on inducing chlorophyll-deficient mutations in barley ( Hordeum vulgare ). 200 seeds per treatment were planted at various distances from the radiation source. Treatments ranged from 0.17 R/day (16.5 R total exposure) to 23.2 R/day (2240 R total exposure). The plants were exposed 20 h per day from time of emergence until harvest (96 days) and the apical spikes harvested from each surviving plant. 20 seeds (at random) from each spike were removed and bulked with those from other spikes within the same treatment to make up the M 1 population. Seeds from non-irradiated plants were also included as a treatment. Up to 5 spikes were harvested from each M 1 plant, planted in greenhouse benches, and M 2 seedlings scored for chlorophyll-deficient mutants. M 1 plant survival and reduction in seed set were approximately the same regardless of the treatment. The frequency of mutations per 10 000 M 2 seedlings from 1.3 for the non-irradiated population to 4.3 for progeny of plants receiving 0.17 R/day. This frequency remained about the same through 1.45 R/day. At 3.17 R/day, the frequency increased to 7.0 and was 45.4 at 23.2 R/day. Although there appears to be a plateau and the low exposures, it is not possible to determine the exact shape of the dose response. A mathematical model with an equation of the form Y = Be cx2 and also a linear-linear model were used to summarize the data. The mutation spectrum from all treatments was 70.6% albina, 17.6% viridis and 11.7% others.

Chlorophyll-deficient mutation frequency in barley following continuous gamma irradiation over a wide range of exposures throughout the life cycle

An experiment was conducted to test the influence of continuous γ-irradiation over a wide range of exposures throughout one life cycle on inducing chlorophyll-deficient mutations in barley ( Hordeum vulgare). 200 seeds per treatment were planted at various distances from the radiation source. Treatments ranged from 0.17 R/day (16.5 R total exposure) to 23.2 R/day (2240 R total exposure). The plants were exposed 20 h per day from time of emergence until harvest (96 days) and the apical spikes harvested from each surviving plant. 20 seeds (at random) from each spike were removed and bulked with those from other spikes within the same treatment to make up the M 1 population. Seeds from non-irradiated plants were also included as a treatment. Up to 5 spikes were harvested from each M 1 plant, planted in greenhouse benches, and M 2 seedlings scored for chlorophyll-deficient mutants. M 1 plant survival and reduction in seed set were approximately the same regardless of the treatment. The frequency of mutations per 10 000 M 2 seedlings from 1.3 for the non-irradiated population to 4.3 for progeny of plants receiving 0.17 R/day. This frequency remained about the same through 1.45 R/day. At 3.17 R/day, the frequency increased to 7.0 and was 45.4 at 23.2 R/day. Although there appears to be a plateau and the low exposures, it is not possible to determine the exact shape of the dose response. A mathematical model with an equation of the form Y= Be cx2 and also a linear-linear model were used to summarize the data. The mutation spectrum from all treatments was 70.6% albina, 17.6% viridis and 11.7% others.

Relation of embryo structure, node position, tillering and depth of planting to the effects of X-rays in barley

Biological, especially genetic, effects of X-rays in barley are influenced by embryo development, node position in M 1 plants, depth of planting and plant tillering. Bud or tillerinitial viability was determined with the vital stain, tetrazolium chloride. Both deeply planted and irradiated seeds exhibited reduced tillering from the bud in the axil of the coleoptile. Mutation rates (frequencies of chlorophyll-deficient M 2 seedlings) were calculated by the M 1 plant, M 1 spike, or M 2 seedling methods. Mutation rates were also determined by each method for apical spikes, primary and secondary axillary spikes, and each node position. These latter rates differed less from one another when scored by the M 1 spike or M 2 seedling methods than when scored by the M 1 plant method. The M 1 spike mutation curve approached closest to linearity for plants with all primary axillary and apical spikes present and with all duplicate mutants excluded. Reliable mutation rates can be calculated from the apical spike alone. Node position on the M 1 plants, with the exception of the fourth node, did not appear to affect mutation rates. Spikes above the fourth node and from secondary axillary tillers frequently had as many or more mutations than the primary axillary spikes. In fact, a higher mutation rate occurred in plants with higher numbers of tillers. Summarized mutation rates of the primaries at the upper nodes were higher than at the lower nodes. The converse was true for the secondaries which also had lower rates than the primaries. Fluctuations in rates were related to variations in embryo structure and to a decrease in the number of nodes (with tillers), spikes, and seedlings per plant. Therefore, the nearly linear mutation rates with increasing dose are probably related to high numbers of tillers which would permit mutant cells to be detected.

ELECTROPHYSIOLOGICAL PROPERTIES OF CA1 AND CA2 APICAL DENDRITES OF RABBIT HIPPOCAMPUS

ArticlesELECTROPHYSIOLOGICAL PROPERTIES OF CA1 AND CA2 APICAL DENDRITES OF RABBIT HIPPOCAMPUSYasuichiro Fujita, and Hideo SakataYasuichiro Fujita, and Hideo SakataPublished Online:01 Mar 1962https://doi.org/10.1152/jn.1962.25.2.209MoreSectionsPDF (2 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Previous Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited BySynaptically Recruited Apical Currents Are Required to Initiate Axonal and Apical Spikes in Hippocampal Pyramidal Cells: Modulation by InhibitionS. Canals, L. López-Aguado, and O. Herreras1 February 2005 | Journal of Neurophysiology, Vol. 93, No. 2Backpropagating action potentials in neurones: measurement, mechanisms and potential functionsProgress in Biophysics and Molecular Biology, Vol. 87, No. 1Optical detection of dendritic spike initiation in hippocampal CA1 pyramidal neuronsNeuroscience, Vol. 118, No. 4Structural Inhomogeneities Differentially Modulate Action Currents and Population Spikes Initiated in the Axon or DendritesL. López-Aguado, J. M. Ibarz, P. Varona, and O. Herreras1 November 2002 | Journal of Neurophysiology, Vol. 88, No. 5Apical and Basal Orthodromic Population Spikes in Hippocampal CA1 In Vivo Show Different Origins and Patterns of PropagationFabian Kloosterman, Pascal Peloquin, and L. Stan Leung1 November 2001 | Journal of Neurophysiology, Vol. 86, No. 5Macroscopic and Subcellular Factors Shaping Population SpikesP. Varona, J. M. Ibarz, L. López-Aguado, and O. Herreras1 April 2000 | Journal of Neurophysiology, Vol. 83, No. 4Modulation of Dendritic Action Currents Decreases the Reliability of Population SpikesL. López-Aguado, J. M. Ibarz, and O. Herreras1 February 2000 | Journal of Neurophysiology, Vol. 83, No. 2The Return of the SpikeNeuron, Vol. 22, No. 4Dendritic Sodium Spikes Are Variable Triggers of Axonal Action Potentials in Hippocampal CA1 Pyramidal NeuronsNeuron, Vol. 21, No. 5Properties of Calcium Spikes Revealed During GABAA Receptor Antagonism in Hippocampal CA1 Neurons From Guinea PigsMasami Miura, Masatomo Yoshioka, Hiroyoshi Miyakawa, Hiroshi Kato, and Ken-Ichi Ito1 November 1997 | Journal of Neurophysiology, Vol. 78, No. 5Action in the Dendrites: A Revisitation of Dendritic Action Potentials29 June 2016 | The Neuroscientist, Vol. 1, No. 6Fast pre-potential generation in rat hippocampal ca1 pyramidal neuronsNeuroscience, Vol. 53, No. 4Long-term loss of paired pulse inhibition in the kainic acid-lesioned hippocampus of the ratNeuroscience, Vol. 28, No. 3Spontaneous EEG spikes in the normal hippocampus. III. Relations to evoked potentialsElectroencephalography and Clinical Neurophysiology, Vol. 69, No. 6Active properties of dendritic membrane examined by current source density analysis in hippocampal CA1 pyramidal neuronsBrain Research, Vol. 399, No. 2Responses of opossum and rat hippocampal CA1 cells to paired stimulus volleysBrain Research Bulletin, Vol. 15, No. 3Chronic failure of inhibition of the CA1 area of the hippocampus following kainic acid lesions of the CA3/4 areaBrain Research, Vol. 295, No. 2Median raphe- and contralateral hippocampus-elicited EEG spikes which correspond to hyperpolarizations of pyramidal cells in the kindled hippocampus of the rabbitBrain Research, Vol. 278, No. 1-2Stereoselectivity of opiate antagonists in rat hippocampus and neocortex: Responses to (+) and (−) isomers of naloxoneNeuroscience, Vol. 7, No. 7Ethanol-induced depressions in cerebellar and hippocampal neurons of mice selectively bred for differences in ethanol sensitivity: An electrophysiological studyPharmacology Biochemistry and Behavior, Vol. 14, No. 2Release of γ-aminobutyrate from the external plexiform layer of the rat olfactory bulb: Possible dendritic involvementNeuroscience, Vol. 5, No. 11Electrophysiological interactions of enkephalins with neuronal circuitry in the rat hippocampus. 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Effects on pyramidal cell activityBrain Research, Vol. 184, No. 2Quantification of synaptic vesicles in hippocampus of aging rats and initial studies of possible relations to neurophysiologyBrain Research Bulletin, Vol. 4, No. 6Evidence for the existence of inhibitory postsynaptic potentials in dendrites and their functional significance in hippocampal pyramidal cells of adult rabbitsBrain Research, Vol. 175, No. 1Hippocampal CA1 region — demonstration of antidromic dendritic spike and dendritic inhibitionBrain Research, Vol. 158, No. 1Impaired synaptic potentiation processes in the hippocampus of aged, memory-deficient ratsBrain Research, Vol. 150, No. 1Electrophysiological properties of so-called inactivation response and their relationship to dendritic activity in hippocampal pyramidal cells of rabbitsBrain Research, Vol. 130, No. 1Effects of diphenylhydantoin and diazepam on hippocampal evoked responsesNeuropharmacology, Vol. 15, No. 3Hippocampal theta rhythm: Intra-hippocampal formation contributionsBrain Research, Vol. 65, No. 1The dependence of hippocampal function on extracellular potassium levelsBiosystems, Vol. 4, No. 1Synaptic organisation of the pigeon's optic tectum: A golgi and current source-density analysisBrain Research, Vol. 27, No. 2Hippocampal responses to neocortical stimulation in the chloralose-anesthetized catElectroencephalography and Clinical Neurophysiology, Vol. 28, No. 3Effect of drugs on the spike complication of hippocampal field potentialsExperimental Neurology, Vol. 19, No. 1Extracellular potential field of antidromically activated CA1 pyramidal neuronsBrain Research, Vol. 3, No. 4Hippocampal functions in learningJournal of Psychiatric Research, Vol. 4, No. 4Electrophysiological studies of hippocampal neurons II. secondary postsynaptic events and single cell unit dischargesElectroencephalography and Clinical Neurophysiology, Vol. 15, No. 3 More from this issue > Volume 25Issue 2March 1962Pages 209-222 https://doi.org/10.1152/jn.1962.25.2.209PubMed13895765History Published online 1 March 1962 Published in print 1 March 1962 Metrics