Search

Mobile health (mHealth) interventions are increasingly used to support community health workers (CHWs) in low-and middle-income countries. As near-peers within their communities, the credibility of CHWs is sometimes questioned—a recognized barrier to their efficacy. Nested within a large, randomized-controlled trial, this qualitative study captured the experiences of South African CHWs, called “Mentor-Mothers,” using tablets and animated videos to promote exclusive breastfeeding. We conducted in-depth telephone interviews with 26 tablet-carrying Mentor-Mothers. We analyzed interview transcripts using a Grounded Theory approach, then developed a theoretical framework, based on an emerging theme, for understanding how tablet technology boosts the perceived credibility of CHWs. Tablet-carrying Mentor-Mothers described an increase in their perceived credibility, which they attributed to overt and signaling effects related to enhanced credibility of (1) their messages, (2) themselves as messengers, and (3) the program employing them. Mobile technology investments in CHWs could enhance their credibility, translating into meaningful investments in the health of under-served communities.

PurposeThe overarching aim of this article is to consider to what extent the perceptions of librarians in Denmark, Germany, Hungary, Iceland, Norway, Poland and Sweden reflect a unified view of their professional role and the role of their institutions in supporting the formation of the public sphere and to what extent the variations reflect national contexts.Design/methodology/approachThe multi-country comparison is based on online questionnaires. The central research questions are how do librarians legitimize the use of public resources to uphold a public library service? How do librarians perceive the role of public libraries as public spaces? How do librarians perceive their professional role and the competencies needed for it? Consideration is given to how the digital and social turns are reflected in the responses.FindingsThe results show evidence of a unified professional culture with clear influences from national contexts. A key finding is that librarians see giving access as central for both legitimizing library services and for the library's role as a public sphere institution. Strong support is shown for the social turn in supporting the formation of the public sphere while the digital turn appears to be a future challenge; one of seemingly increased importance due to the pandemic.Research limitations/implicationsThis study shows that libraries across the seven countries have expanded beyond simply providing public access to their book-based collections and now serve as social, learning and creative spaces: both in the physical library and digitally. Qualitative research is needed concerning librarians' notions of public libraries and librarianship, which will provide a more in-depth understanding of the changing professional responsibilities and how public libraries recruit the associated competencies.Originality/valueThe article provides a much needed insight into how librarians perceive the role of public libraries in supporting the formation of the public sphere and democratic processes, as well as their own role.

IntroductionAs of July 2022, a little over one-third of Guatemalans were fully vaccinated. While COVID-19 vaccination rates are not officially reported nationally by racial/ethnic groups, non-governmental organisations and reporters have observed that COVID-19 vaccination rates are especially low among high-risk Indigenous populations. We conducted one of the first studies on COVID-19 vaccine acceptance in Indigenous populations in the Central Highlands of Guatemala, which aimed to better understand the barriers to COVID-19 vaccine uptake and how to improve vaccine promotional campaigns.MethodsIn November 2021, we conducted eight focus group discussions (FGDs) with 42 Indigenous men and women and 16 in-depth interviews (IDIs) with community health workers, nurses and physicians in Chimaltenango and Sololá. Using a participatory design approach, our qualitative analysis used constant comparative methods to understand the inductive and deductive themes from the FGD and IDI transcripts.ResultsWe found three major overarching barriers to vaccination within the sampled population: (1) a lack of available easily understandable, linguistically appropriate and culturally sensitive COVID-19 vaccine information; (2) vaccine access and supply issues that prevented people from being vaccinated efficiently and quickly; and (3) widespread misinformation and disinformation that prey on people’s fears of the unknown and mistrust of the medical establishment and government.ConclusionWhen developing COVID-19 vaccine messages, content should be culturally relevant, appropriate for low-literacy populations and in the languages that people prefer to speak. Promotional materials should be in multiple modalities (print, radio and social media) and also have specific Maya cultural references (dress, food and concepts of disease) to ensure messaging connects with intended targets. This study supports the need for more robust research into best practices for communicating about COVID-19 vaccines to marginalised communities globally and suggests that policy makers should invest in targeted local solutions to increase vaccine uptake.

Background: Health professions education has undergone major changes with the advent and adoption of digital technologies worldwide. Objective: This study aims to map the existing evidence and identify gaps and research priorities to enable robust and relevant research in digital health professions education. Methods: We searched for systematic reviews on the digital education of practicing and student health care professionals. We searched MEDLINE, Embase, Cochrane Library, Educational Research Information Center, CINAHL, and gray literature sources from January 2014 to July 2020. A total of 2 authors independently screened the studies, extracted the data, and synthesized the findings. We outlined the key characteristics of the included reviews, the quality of the evidence they synthesized, and recommendations for future research. We mapped the empirical findings and research recommendations against the newly developed conceptual framework. Results: We identified 77 eligible systematic reviews. All of them included experimental studies and evaluated the effectiveness of digital education interventions in different health care disciplines or different digital education modalities. Most reviews included studies on various digital education modalities (22/77, 29%), virtual reality (19/77, 25%), and online education (10/77, 13%). Most reviews focused on health professions education in general (36/77, 47%), surgery (13/77, 17%), and nursing (11/77, 14%). The reviews mainly assessed participants’ skills (51/77, 66%) and knowledge (49/77, 64%) and included data from high-income countries (53/77, 69%). Our novel conceptual framework of digital health professions education comprises 6 key domains (context, infrastructure, education, learners, research, and quality improvement) and 16 subdomains. Finally, we identified 61 unique questions for future research in these reviews; these mapped to framework domains of education (29/61, 47% recommendations), context (17/61, 28% recommendations), infrastructure (9/61, 15% recommendations), learners (3/61, 5% recommendations), and research (3/61, 5% recommendations). Conclusions: We identified a large number of research questions regarding digital education, which collectively reflect a diverse and comprehensive research agenda. Our conceptual framework will help educators and researchers plan, develop, and study digital education. More evidence from low- and middle-income countries is needed., Journal of Medical Internet Research, 24 (3), ISSN:1438-8871

Sensory circuits adapt to changes in the external world or the animal9s internal state through the actions of neuromodulators. Synapses are key sites at which neuromodulators act but it is not known how they alter the amount of information transmitted. We investigated this question in the context of the diurnal regulation of visual processing in larval zebrafish, focusing on ribbon-type synapses of retinal bipolar cells. We demonstrate that contrast-sensitivity peaks in the afternoon accompanied by an average four-fold increase in the Shannon information transmitted at individual active zones. This increase reflects higher synaptic gain, lower spontaneous noise, reduced variability of stimulus-evoked release and improved temporal precision. Simultaneously, an increase in the probability of multivesicular events with larger information content increases the efficiency of information transmission (bits per vesicle) by factors of 2-3. The neuromodulator dopamine contributes to all these changes in synaptic function, although ON and OFF visual channels are differentially affected. Multivesicular release is a property of synapses in many parts of the brain and this study demonstrates that potentiation by neuromodulators can both increase the amount of information that is transmitted and the efficiency of transmission, revealing a previously unknown mechanism for adjusting neural processing.

BACKGROUND Health professions education has undergone major changes with the advent and adoption of digital technologies worldwide. OBJECTIVE This study aims to map the existing evidence and identify gaps and research priorities to enable robust and relevant research in digital health professions education. METHODS We searched for systematic reviews on the digital education of practicing and student health care professionals. We searched MEDLINE, Embase, Cochrane Library, Educational Research Information Center, CINAHL, and gray literature sources from January 2014 to July 2020. A total of 2 authors independently screened the studies, extracted the data, and synthesized the findings. We outlined the key characteristics of the included reviews, the quality of the evidence they synthesized, and recommendations for future research. We mapped the empirical findings and research recommendations against the newly developed conceptual framework. RESULTS We identified 77 eligible systematic reviews. All of them included experimental studies and evaluated the effectiveness of digital education interventions in different health care disciplines or different digital education modalities. Most reviews included studies on various digital education modalities (22/77, 29%), virtual reality (19/77, 25%), and online education (10/77, 13%). Most reviews focused on health professions education in general (36/77, 47%), surgery (13/77, 17%), and nursing (11/77, 14%). The reviews mainly assessed participants’ skills (51/77, 66%) and knowledge (49/77, 64%) and included data from high-income countries (53/77, 69%). Our novel conceptual framework of digital health professions education comprises 6 key domains (context, infrastructure, education, learners, research, and quality improvement) and 16 subdomains. Finally, we identified 61 unique questions for future research in these reviews; these mapped to framework domains of education (29/61, 47% recommendations), context (17/61, 28% recommendations), infrastructure (9/61, 15% recommendations), learners (3/61, 5% recommendations), and research (3/61, 5% recommendations). CONCLUSIONS We identified a large number of research questions regarding digital education, which collectively reflect a diverse and comprehensive research agenda. Our conceptual framework will help educators and researchers plan, develop, and study digital education. More evidence from low- and middle-income countries is needed.

BackgroundEnsuring access to accurate and actionable health information is crucial during the COVID-19 pandemic, especially in low-resource settings. Among marginalized groups, there are disparities in access to information, along with significant mistrust of government sources. Non-governmental organizations (NGOs) involved in community-level health education can play an important role in bridging mistrust and targeting information to reach vulnerable populations. There is a lack of research on the experiences and needs of organizations involved in disseminating health information during the pandemic. MethodsThis study uses a qualitative approach to investigate the current strategies, challenges, and needs of community-based organizations involved in COVID-19 public education. From May to June 2020, we conducted 19 semi-structured interviews with leaders of organizations in South Africa and Zambia. Participants were asked a series of open-ended questions in three domains: 1) the impact of the pandemic on the communities served by the organization, 2) their COVID-19 response, and 3) organization needs and challenges during the pandemic. Interviews were recorded, transcribed, and coded using thematic analysis. Coding and analysis were conducted by four study authors and every interview was independently coded by 2 separate authors to maximize internal validity and consistency.Results5 themes relevant to the roles and challenges of locally active NGO’s were identified: (1) they intimately understand community needs during the pandemic; (2) they adapt to pandemic constraints to continue supporting vulnerable populations; (3) they play a unique role in educating the public about COVID-19 due to established access and trust within communities; (4) they are able to customize health education and information to address nuanced needs of local communities served; and (5) they need external support to effectively respond to the pandemic.ConclusionsOverall, our study contributes a deeper understanding of the role of NGOs in providing needed support and customized health education for vulnerable communities during a global public health crisis. To maximize their ability to support their communities, NGO’s would benefit from access to educational resources designed to be easily modified, support in navigating technological and safety challenges during the pandemic, and sustainable funding.

The action potential and its all-or-none nature is fundamental to neural communication. These binary spikes are used by neurons to signal that a decision has been made; that their membrane potential has crossed a threshold either due to synaptic inputs or intrinsic mechanisms. Canonically the action potential is initiated once voltage-gated Na+ (Nav) channels are activated, these channels underpin the rapid upstroke of the action potential and their rapid kinetics give rise to the all-or-none nature of the action potential. Here we show that cerebrospinal fluid contacting neurons (CSFcNs) surrounding the central canal of the mouse spinal cord employ a different strategy. Rather than using Nav channels to generate binary spikes, CSFcNs use two different types of voltage-gated Ca2+ channel, enabling spikes of different amplitude. T-type Ca2+ channels are required for spontaneous spiking and generate lower amplitude spikes which signal purinergic inputs. In contrast large amplitude spikes require high voltage activated Cd2+ sensitive Ca2+ channels and these larger spikes signal cholinergic inputs. Our results show that the neurotransmitter impinging upon CSFcNs can be differentially signalled by the spike amplitude and this is supported by different types of voltage-gated Ca2+ channel. CSFcNs have recently been shown to be integral to coordinating posture and motor output in zebrafish and lamprey, our results show that these neurons can employ novel mechanisms to integrate and signal the neurotransmitter systems in which they are embedded.

SummarySensory systems must reduce the transmission of redundant information to function efficiently. One strategy is to continuously adjust the sensitivity of neurons to suppress responses to common features of the input while enhancing responses to new ones. Here we image both the excitatory synaptic inputs and outputs of retinal ganglion cells to understand how such dynamic predictive coding is implemented in the analysis of spatial patterns. Synapses of bipolar cells become tuned to orientation through presynaptic inhibition generating lateral antagonism in the orientation domain. Individual ganglion cells receive excitatory synapses tuned to different orientations but feedforward inhibition generates a high-pass filter that only transmits the initial activation of these inputs, thereby removing redundancy. These results demonstrate how a dynamic predictive code can be implemented by circuit motifs common to many parts of the brain.

Although a large number of students around the world attend vocational schools, there is little evidence about what factors matter for learning in these schools. Using data on approximately 1,400 vocational students in one eastern province in China, we employ a student fixed-effects model to identify whether teacher enterprise experience, direct occupational experience, and not just program training increases students’ technical skills. We find this to be the case, especially for students who began the program as high performers. In contrast, “professional certification” that is given to teachers who participate in short-term training programs has no positive impact.

The potential of conversation-based programming (i.e., language cafes and conversation groups) for supporting immigrant integration is explored in a case-based study on the Sprakhornan (“language corner”) program at the City Library in Malmo, Sweden. The methodology includes participant observation, interviews with program participants, a focus group with program volunteers, and a questionnaire. The basis of the study's theoretical framework is social capital theory, information grounds theory, and a multi-dimensional model of integration. Results indicate that, first, such a program offers a unique opportunity for many participants to use their Swedish language skills and gain conversational competence. Second, the program supports integration through information exchange during the informal conversations. Third, it offers participants a space for social interaction with Swedes and other immigrants. Conversation-based programming in libraries can foster integration by supporting language learning, facilitating the expansion of participants' social networks, and increasing social capital in the form of increased knowledge and information about the new country.

In this review we take a physiological perspective on the role of voltage-gated potassium channels in an identified neuron in the auditory brainstem. The large number of KCN genes for potassium channel subunits and the heterogeneity of the subunit combination into K(+) channels make identification of native conductances especially difficult. We provide a general pharmacological and biophysical profile to help identify the common voltage-gated K(+) channel families in a neuron. Then we consider the physiological role of each of these conductances from the perspective of the principal neuron in the medial nucleus of the trapezoid body (MNTB). The MNTB is an inverting relay, converting excitation generated by sound from one cochlea into inhibition of brainstem nuclei on the opposite side of the brain; this information is crucial for binaural comparisons and sound localization. The important features of MNTB action potential (AP) firing are inferred from its inhibitory projections to four key target nuclei involved in sound localization (which is the foundation of auditory scene analysis in higher brain centres). These are: the medial superior olive (MSO), the lateral superior olive (LSO), the superior paraolivary nucleus (SPN) and the nuclei of the lateral lemniscus (NLL). The Kv families represented in the MNTB each have a distinct role: Kv1 raises AP firing threshold; Kv2 influences AP repolarization and hyperpolarizes the inter-AP membrane potential during high frequency firing; and Kv3 accelerates AP repolarization. These actions are considered in terms of fidelity of transmission, AP duration, firing rates and temporal jitter. An emerging theme is activity-dependent phosphorylation of Kv channel activity and suggests that intracellular signalling has a dynamic role in refining neuronal excitability and homeostasis.

Mitral cells are the primary output of the olfactory bulb, projecting to many higher brain areas. Understanding how mitral cells process and transmit information is key to understanding olfactory perception. Mitral dendrites possess high densities of voltage-gated channels, are able to initiate and propagate orthodromic and antidromic action potentials, and release neurotransmitter. We show that mitral cells also possess a low-voltage-activated T-type Ca2+current. Immunohistochemistry shows strong Cav3.3 labeling in the primary dendrite and apical tuft with weaker staining in basal dendrites and no staining in somata. A low-voltage-activated Ca2+current activates from −68 mV, is blocked by 500 μM Ni2+and 50 μM NNC 55-0396, but is insensitive to 50 μM Ni2+and 500 μM isradipine. 2-photon Ca2+imaging shows that T channels are functionally expressed in the primary dendrite where their activity determines the resting [Ca2+] and are responsible for subthreshold voltage-dependent Ca2+changes previously observed in vivo. Application of the group 1 mGluR agonist dihydroxyphenylglycine (DHPG) (50 μM) robustly upregulates T-channel current in the primary and apical tuft dendrite. Olfactory nerve stimulation generates a long-lasting depolarization, and we show that mGluRs recruit T channels to contribute ∼36% of the voltage integral of this depolarization. The long-lasting depolarization results in sustained firing and block of T channels decreased action potential firing by 84.1 ± 4.6%. Therefore upregulation of T channels by mGluRs is required for prolonged firing in response to olfactory nerve input.

Most current clamp studies trigger action potentials (APs) by step current injection through the recording electrode and assume that the resulting APs are essentially identical to those triggered by orthodromic synaptic inputs. However this assumption is not always valid, particularly when the synaptic conductance is of large magnitude and of close proximity to the axon initial segment. We addressed this question of similarity using the Calyx of Held/MNTB synapse; we compared APs evoked by long duration step current injections, short step current injections and orthodromic synaptic stimuli. Neither injected current protocol evoked APs that matched the evoked orthodromic AP waveform, showing differences in AP height, half-width and after-hyperpolarization. We postulated that this 'error' could arise from changes in the instantaneous conductance during the combined synaptic and AP waveforms, since the driving forces for the respective ionic currents are integrating and continually evolving over this time-course. We demonstrate that a simple Ohm's law manipulation of the EPSC waveform, which accounts for the evolving driving force on the synaptic conductance during the AP, produces waveforms that closely mimic those generated by physiological synaptic stimulation. This stimulation paradigm allows supra-threshold physiological stimulation (single stimuli or trains) without the variability caused by quantal fluctuation in transmitter release, and can be implemented without a specialised dynamic clamp system. Combined with pharmacological tools this method provides a reliable means to assess the physiological roles of postsynaptic ion channels without confounding affects from the presynaptic input.

This study examined the effects of marital status and family income on the self-esteem of 292 African American mothers. Counter to previous studies with European American mothers, family income moderated the effects of marital status. Those mothers with higher family income had higher self-esteem, regardless of their marital status. For those with less family income, married mothers had much higher self-esteem than unmarried mothers. Low-income married mothers had the same levels of self-esteem as high income mothers. It was concluded that financial resources can buffer the effects of being single, and being married can buffer the effects of being low income. Policy initiatives that focus on reducing the financial hardship on single mothers and increasing the marriage rate among lower income parents were also discussed.

The medial nucleus of the trapezoid body (MNTB) is specialized for high frequency firing by expression of Kv3 channels, which minimize action potential (AP) duration, and Kv1 channels, which suppress multiple AP firing, during each calyceal giant EPSC. However, the outward K(+) current in MNTB neurons is dominated by another unidentified delayed rectifier. It has slow kinetics and a peak conductance of approximately 37 nS; it is half-activated at -9.2 +/- 2.1 mV and half-inactivated at -35.9 +/- 1.5 mV. It is blocked by several non-specific potassium channel antagonists including quinine (100 microm) and high concentrations of extracellular tetraethylammonium (TEA; IC(50) = 11.8 mM), but no specific antagonists were found. These characteristics are similar to recombinant Kv2-mediated currents. Quantitative RT-PCR showed that Kv2.2 mRNA was much more prevalent than Kv2.1 in the MNTB. A Kv2.2 antibody showed specific staining and Western blots confirmed that it recognized a protein approximately 110 kDa which was absent in brainstem tissue from a Kv2.2 knockout mouse. Confocal imaging showed that Kv2.2 was highly expressed in axon initial segments of MNTB neurons. In the absence of a specific antagonist, Hodgkin-Huxley modelling of voltage-gated conductances showed that Kv2.2 has a minor role during single APs (due to its slow activation) but assists recovery of voltage-gated sodium channels (Nav) from inactivation by hyperpolarizing interspike potentials during repetitive AP firing. Current-clamp recordings during high frequency firing and characterization of Nav inactivation confirmed this hypothesis. We conclude that Kv2.2-containing channels have a distinctive initial segment location and crucial function in maintaining AP amplitude by regulating the interspike potential during high frequency firing.

The relationship between microRNA (miRNA) regulation and the specification of behavior is only beginning to be explored. We found that mutation of a single miRNA locus ( miR-iab4/iab8 ) in Drosophila larvae affects the animal’s capacity to correct its orientation if turned upside down (self-righting). One of the miRNA targets involved in this behavior is the Hox gene Ultrabithorax , whose derepression in two metameric neurons leads to self-righting defects. In vivo neural activity analysis reveals that these neurons, the self-righting node (SRN), have different activity patterns in wild type and miRNA mutants, whereas thermogenetic manipulation of SRN activity results in changes in self-righting behavior. Our work thus reveals a miRNA-encoded behavior and suggests that other miRNAs might also be involved in behavioral control in Drosophila and other species.

Motion anticipation allows the visual system to compensate for the slow speed of phototransduction so that a moving object can be accurately located. This correction is already present in the signal that ganglion cells send from the retina but the biophysical mechanisms underlying this computation are not known. Here we demonstrate that motion anticipation is computed autonomously within the dendritic tree of each ganglion cell and relies on feedforward inhibition. The passive and non-linear interaction of excitatory and inhibitory synapses enables the somatic voltage to encode the actual position of a moving object instead of its delayed representation. General rather than specific features of the retinal connectome govern this computation: an excess of inhibitory inputs over excitatory, with both being randomly distributed, allows tracking of all directions of motion, while the average distance between inputs determines the object velocities that can be compensated for. DOI: http://dx.doi.org/10.7554/eLife.06250.001, eLife digest The retina is a structure at the back of the eye that converts light into nerve impulses, which are then processed in the brain to produce the images that we see. It normally takes about one-tenth of a second for the retina to send a signal to the brain after an object first moves into view. This is about the same time it takes a tennis ball to travel several meters during a tennis match, yet we are still able to see where the moving tennis ball is in real time. This is because a process called ‘motion anticipation’ is able to compensate for the delay in processing the position of a moving object. However, it was not known precisely how motion anticipation occurs. Inside the retina, cells called photoreceptors detect light and ultimately send signals (via some intermediate cell types) to nerve cells known as retinal ganglion cells. These signals can either excite a retinal ganglion cell to cause it to send an electrical signal to the brain, or inhibit it, which temporarily prevents electrical activity. Each cell receives signals from several photoreceptors, which each connect to a different site along branch-like structures called dendrites that project out of the retinal ganglion cells. Johnston and Lagnado have now investigated how motion anticipation occurs in the retina by using electrical recordings of the activity in the retinas of goldfish combined with computer simulations of this activity. This revealed inhibitory signals, sent from photoreceptors to retinal ganglion cells via a type of intermediate cell (called amacrine cells), play a key role in motion anticipation. The ability to track motion effectively in all directions requires more inhibitory signals to be sent to the dendrites of a retinal ganglion cell than excitatory signals. These two types of input must also be randomly distributed across the cell. Furthermore, it is the density of these input sites on a dendrite that determines how well the retina can compensate for the motion of a fast-moving object. The building blocks required for motion anticipation in the retina are also found in visual areas higher in the brain. Therefore, further work may reveal that higher visual areas also use this mechanism to predict the future location of moving objects. DOI: http://dx.doi.org/10.7554/eLife.06250.002

Summary Two complementary studies have resolved the circuitry underlying green–blue color discrimination in the retina. A blue-sensitive interneuron provides the inhibitory signal required for computing green–blue color opponency.

Mitral cells express low-voltage activated Cav3.3 channels on their distal apical tuft dendrites (McKay et al., 2006; Johnston and Delaney, 2010). They also discharge Na+-dependent dendritic action potentials and release glutamate from these dendrites. Around resting membrane potentials, between −65 and −50 mV, Cav3.x channels are a primary determinant of cytoplasmic [Ca2+]. In this study using C57 mice, we present evidence that subthreshold Cav3.x-mediated Ca2+influx modulates action potential evoked transmitter release and directly drives asynchronous release from distal tuft dendrites. Presynaptic hyperpolarization and selective block of Cav3.x channels with Z941 (Tringham et al., 2012) reduce mitral-to-mitral EPSP amplitude, increase the coefficient of variation of EPSPs, and increase paired-pulse ratios, consistent with a reduced probability of transmitter release. Both hyperpolarization and Cav3.x channel blockade reduce steady-state cytoplasmic [Ca2+] in the tuft dendrite without reducing action potential evoked Ca2+influx, suggesting that background [Ca2+] modulates evoked release. We demonstrate that Cav3.x-mediated Ca2+influx from even one mitral cell at membrane potentials between −65 and −50 mV is sufficient to produce feedback inhibition from periglomerular neurons. Deinactivation of Cav3.x channels by hyperpolarization increases T-type Ca2+influx upon repolarization and increases feedback inhibition to produce subthreshold modulation of the mitral–periglomerular reciprocal circuit.

Neurons in the visual system vary widely in the spatiotemporal properties of their receptive fields (RFs), and understanding these variations is key to elucidating how visual information is processed. We present a new approach for mapping RFs based on the filtered back projection (FBP), an algorithm used for tomographic reconstructions. To estimate RFs, a series of bars were flashed across the retina at pseudo-random positions and at a minimum of five orientations. We apply this method to retinal neurons and show that it can accurately recover the spatial RF and impulse response of ganglion cells recorded on a multi-electrode array. We also demonstrate its utility for in vivo imaging by mapping the RFs of an array of bipolar cell synapses expressing a genetically encoded Ca(2+) indicator. We find that FBP offers several advantages over the commonly used spike-triggered average (STA): (i) ON and OFF components of a RF can be separated; (ii) the impulse response can be reconstructed at sample rates of 125 Hz, rather than the refresh rate of a monitor; (iii) FBP reveals the response properties of neurons that are not evident using STA, including those that display orientation selectivity, or fire at low mean spike rates; and (iv) the FBP method is fast, allowing the RFs of all the bipolar cell synaptic terminals in a field of view to be reconstructed in under 4 min. Use of the FBP will benefit investigations of the visual system that employ electrophysiology or optical reporters to measure activity across populations of neurons.

In this review we take a physiological perspective on the role of voltage-gated potassium channels in an identified neuron in the auditory brainstem. The large number of KCN genes for potassium channel subunits and the heterogeneity of the subunit combination into K(+) channels make identification of native conductances especially difficult. We provide a general pharmacological and biophysical profile to help identify the common voltage-gated K(+) channel families in a neuron. Then we consider the physiological role of each of these conductances from the perspective of the principal neuron in the medial nucleus of the trapezoid body (MNTB). The MNTB is an inverting relay, converting excitation generated by sound from one cochlea into inhibition of brainstem nuclei on the opposite side of the brain; this information is crucial for binaural comparisons and sound localization. The important features of MNTB action potential (AP) firing are inferred from its inhibitory projections to four key target nuclei involved in sound localization (which is the foundation of auditory scene analysis in higher brain centres). These are: the medial superior olive (MSO), the lateral superior olive (LSO), the superior paraolivary nucleus (SPN) and the nuclei of the lateral lemniscus (NLL). The Kv families represented in the MNTB each have a distinct role: Kv1 raises AP firing threshold; Kv2 influences AP repolarization and hyperpolarizes the inter-AP membrane potential during high frequency firing; and Kv3 accelerates AP repolarization. These actions are considered in terms of fidelity of transmission, AP duration, firing rates and temporal jitter. An emerging theme is activity-dependent phosphorylation of Kv channel activity and suggests that intracellular signalling has a dynamic role in refining neuronal excitability and homeostasis.

Our study re-examines the relationship between parenting and school performance among Asian students. We use two sources of data: wave I of the Adolescent Health Longitudinal Survey (Add Health), and waves I and II of the Taiwan Educational Panel Survey (TEPS). Analysis using Add Health reveals that the Asian-American/European-American difference in the parenting—school performance relationship is due largely to differential sample sizes. When we select a random sample of European-American students comparable to the sample size of Asian-American students, authoritarian parenting also shows no effect for European-American students. Furthermore, analysis of TEPS shows that authoritarian parenting is negatively associated with children’s school achievement, while authoritative parenting is positively associated. This result for Taiwanese Chinese students is similar to previous results for European-American students in the US.