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This study examined the perceptions of 15 teachers and 103 middle school students at a progressive private school located in Mumbai, India to determine their support for the use of mobile phones in the classroom, their perceptions of the mobile phone features that are beneficial for school-related work, and the instructional benefits and barriers to mobile phone use prior to beginning a mobile phone pilot program. The results indicated that most teachers (86%) and students (92%) supported the use of mobile phones in the classroom while those remaining voiced uncertainties. The participants perceived many mobile phone features as being useful in the classroom, but the teachers and students significantly differed in their views. Participant responses revealed little concern about most of the barriers reported in the literature; both teachers and students were least concerned about the use of mobile phones causing a disruption to learning.

Dye localization and destaining release for the fluorescent styryl dye FM1-43 were tested by internalized dye photolysis with diaminobenzidine. An electron-dense reaction product showed that synaptic vesicles contained outstanding amounts of FM1-43. The dye's detection in the vesicles is attributed to the addition of 3- (3-cholamidopropyl)dimethylammonio -1-propanesulfonate, which enhanced dye fluorescence and magnitude.

Naturally occurring isoforms of the decapeptide gonadotropin-releasing hormone (GnRH) share residues 1-4 and 9-10. lGnRH-III, the third isoform isolated in the sea lamprey has no endocrine effect in mammals but shows a direct antiproliferative effect on human breast, prostate and endometrial cancer cell lines. To investigate these features, residues 5-8 of lGnRH-III were systematically replaced with Ala. The ability of the synthetic analogs to interact with receptors on MDA-MB 231 human breast cancer cells and their effect on the growth of the same cell line were investigated. [Ala6]lGnRH-III and [Ala7]lGnRH-III have neither receptor binding nor antiproliferative activity. Replacement of His5 with Ala resulted in an analog that binds to the receptor but does not have antiproliferative activity. The results are in agreement with previous reports that modifications of Lys at position 8 are well tolerated.

The number of vesicles released at excitatory synapses and the number of release sites per synaptic connection are key determinants of information processing in the cortex, yet they remain uncertain. Here we show that the number of functional release sites and the number of anatomically identified synaptic contacts are equal at connections between spiny stellate and pyramidal cells in rat barrel cortex. Moreover, our results indicate that the amount of transmitter released per synaptic contact is independent of release probability and the intrinsic release probability is high. These properties suggest that connections between layer 4 and layer 2/3 are tuned for reliable transmission of spatially distributed, timing-based signals.

1. Dual whole-cell recordings were made from pairs of synaptically coupled excitatory neurones in the 'barrel field' in layer (L) 4 in slices of young (postnatal day 12-15) rat somatosensory cortex. The majority of interconnected excitatory neurones were spiny stellate cells with an asymmetrical dendritic arborisation largely confined to a single barrel. The remainder were star pyramidal cells with a prominent apical dendrite terminating in L2/3 without forming a tuft. 2. Excitatory synaptic connections were examined between 131 pairs of spiny L4 neurones. Single presynaptic action potentials evoked unitary EPSPs with a peak amplitude of 1.59 +/- 1.51 mV (mean +/- s. d.), a latency of 0.92 +/- 0.35 ms, a rise time of 1.53 +/- 0.46 ms and a decay time constant of 17.8 +/- 6.3 ms. 3. At 34-36 C, the coefficient of variation (c.v.) of the unitary EPSP amplitude was 0. 37 +/- 0.16 and the percentage of failures to evoke an EPSP was 5.3 +/- 7.8 %. The c.v. and failure rate decreased with increasing amplitude of the unitary EPSP. 4. Postsynaptic glutamate receptors in spiny L4 neurones were of the AMPA and NMDA type. At -60 mV in the presence of 1 mM Mg2+, NMDA receptors contributed 39.3 +/- 12.5 % to the EPSP integral. In Mg2+-free solution, the NMDA receptor/AMPA receptor ratio of the EPSC was 0.86 +/- 0.64. 5. The number of putative synaptic contacts established by the projection neurone with the target neurone varied between two and five with a mean of 3.4 +/- 1.0 (n = 11). Synaptic contacts were exclusively found in the barrel in which the cell pair was located and were preferentially located on secondary to quarternary dendritic branches. Their mean geometric distance from the soma was 68.8 +/- 37.4 microm (range, 33.4-168.0 microm). The number of synaptic contacts and mean EPSP amplitude showed no significant correlation. 6. The results suggest that in L4 of the barrel cortex synaptic transmission between spiny neurones is largely restricted to a single barrel. The connections are very reliable, probably due to a high release probability, and have a high efficacy because of the compact structure of the dendrites and axons of spiny neurones. Intrabarrel connections thus function to amplify and distribute the afferent thalamic activity in the vertical directions of a cortical column.

Substance P (SP)-ir and opioid-ir structures were studied in the cat main olfactory bulb (MOB), accessory olfactory bulb (AOB), and olfactory peduncle. In the MOB, the opioid-ir and the majority of the SP-ir neurons belong to the granule cell type. SP-ir granule cells reside in the deeper granule cell layer, whereas opioid-ir granule cells reside in the superficial granule cell layer, internal plexiform, and mitral cell layer. Many granule cells are observed in the external plexiform and glomerular layer. Other granule cells were found in the bulbar/peduncular white matter, the taenia tecta, and the genu of the corpus callosum. A new substance P-ir cell type was identified in the glomerular layer. This cell type was also identified by using the technique of intracellular injection of Lucifer Yellow. The cell type corresponds neither to the external tufted type nor to the short axon cell types described so far. The AOB resembles the MOB with respect to large numbers of SP-ir and opioid-ir granule cells. In addition, a few opioid-ir neurons, probably superficial mitral cells, were found in the glomerular layer. The AOB is surrounded by islands of immunoreactive granule cells, which connect to the granule cell layer by extremely long processes. Opioid-ir and SP-ir beaded axons pass through the olfactory peduncle terminating on granule cells, and ascend as far as the glomerular layer. All subdivisions of the anterior olfactory nucleus (AON) contain immunoreactive terminal fields. Afferent fibers and terminal plexuses derive from a population of immunoreactive neurons located predominantly in the region of the septo-olfactory junction. They have large somata. Their axons form recurrent collaterals, some of which run rostrally in the peduncular white matter. Others ascend caudally towards the septal region. The fibers seem to remain ipsilaterally, since the olfactory limb of the anterior commissure and the commissure proper are devoid of SP-ir and opioid-ir fibers. During development SP and opioid immunoreactivity were found only in differentiated granule cells. The peptides were not detectable in migrating or immature granule cells, as identified in Golgi-impregnated material. The granule cell population largely develops during postnatal life. The number of opioid-ir granule cells increases slowly and continuously, reaching the adult level not before the sixth postnatal month. Strikingly, SP-ir granule cell number increases fast and reaches a transient peak during the second month. Thereafter it declines (40% decrease) to the adult density, which is similar to that of opioid-ir granule cells.