Increasing Accessibility to Neuroscience through Translation: Going beyond the English Language.

Declaring the 1990s as The Decade of the Brain put the field of neuroscience at the forefront of public attention, with the nervous system becoming a subject of increasing interest in popular media. Although this has generally brought large swaths of the public closer to neuroscience, most current research is published and disseminated in a single language: English. This is unsurprising as English is indeed the lingua franca in scientific circles, but people around the world communicate in many other languages. To make neuroscience accessible to a larger audience, we share an initiative to translate the Knowing Neurons platform into a second language: Spanish. This collaborative project integrates humanities and STEM academic programs to make use of bilingual university students, in association with professional linguists and neuroscientists, to translate scientific content into a relatable format to Spanish speakers regardless of their country of origin. The translation effort was piloted within the framework of undergraduate outreach courses at the University of California, Los Angeles, and is coupled with outreach components targeting the Spanish-speaking community to promote this new resource. This project aims to foster an environment where the neuroscientific interests of the public, college students, instructors, and researchers coalesce in a unified space. We hope that opening new lines of communication with traditionally underrepresented communities might help combat the persistent lack of diversity in neuroscience (and STEM) that is currently seen in academia. We also provide an outline to inspire others to translate these, and similar resources, into other languages.

An Undergraduate Student-Led Neuroscience Outreach Program Shows Promise in Shifting Teen Attitudes About Drugs.

Drug Outreach, Promoting Awareness (DOPA) is an undergraduate outreach program for local high school students designed to convey the neurobiological basis, risks, and addictive potential of commonly abused drugs. Here we describe DOPA and evaluate the program, including its impact on high school student attitudes about drug harm risk and addiction. Undergraduate neuroscience students versed in the neurobiology, physiology, and policy of drugs are trained in active learning methods, enabling them to create engaging and interactive classroom-based educational materials. Survey results showed that participation in DOPA increased high school student perceptions of the addictive potential and harm risk of drugs, which studies have shown to be inversely correlated with drug-taking. High school students also responded positively to the interactive nature of the program. These findings demonstrate how extensively trained undergraduates who are close peers to high school students can effectively lead science outreach initiatives and shift adolescent attitudes about drugs.

Quantitative assessments reveal improved neuroscience engagement and learning through outreach.

Lack of resources and exposure to neuroscience in K-12 education has resulted in a limited number of K-12 students pursuing higher education in the field. Meanwhile, the rapid expansion of the field of neuroscience has encouraged many higher educational institutes to offer neuroscience majors. This has opened up the opportunity to engage faculty, as well as graduate and undergraduate students in bringing the most needed knowledge and awareness about neuroscience into K-12 classrooms. However, undergraduate neuroscience curricula have limited formal opportunities to engage in outreach, and few existing programs have assessments to determine their effectiveness. To address these needs, we developed quantitative assessment tools that complement an existing neuroscience outreach program-Project Brainstorm-at the University of California, Los Angeles (UCLA). 29 UCLA undergraduates enrolled in the 2016 and 2017 programs participated in this study, along with 298 K-12 students from local schools across the Los Angeles area. In undergraduate students, we assessed (a) improvement in students' teaching/communication abilities across the course of the outreach program, and (b) confidence in explaining neuroscience topics and interest in pursuing teaching career. In K-12 students, we evaluated (a) knowledge gain in neuroscience topics and (b) interest in pursuing higher education. Overall, Project Brainstorm showed significant improvement in all the above-mentioned categories. The assessment tools and data presented here provide a data-driven approach for optimizing neuroscience outreach programs and can easily be adapted to other outreach programs within neuroscience and in other STEM fields.

A putative vesicular transporter expressed in Drosophila mushroom bodies that mediates sexual behavior may define a neurotransmitter system.

Vesicular transporters are required for the storage of all classical and amino acid neurotransmitters in synaptic vesicles. Some neurons lack known vesicular transporters, suggesting additional neurotransmitter systems remain unidentified. Insect mushroom bodies (MBs) are critical for several behaviors, including learning, but the neurotransmitters released by the intrinsic Kenyon cells (KCs) remain unknown. Likewise, KCs do not express a known vesicular transporter. We report the identification of a novel Drosophila gene portabella (prt) that is structurally similar to known vesicular transporters. Both larval and adult brains express PRT in the KCs of the MBs. Additional PRT cells project to the central complex and optic ganglia. prt mutation causes an olfactory learning deficit and an unusual defect in the male's position during copulation that is rescued by expression in KCs. Because prt is expressed in neurons that lack other known vesicular transporters or neurotransmitters, it may define a previously unknown neurotransmitter system responsible for sexual behavior and a component of olfactory learning.

Mutation of the Drosophila vesicular GABA transporter disrupts visual figure detection.

The role of gamma amino butyric acid (GABA) release and inhibitory neurotransmission in regulating most behaviors remains unclear. The vesicular GABA transporter (VGAT) is required for the storage of GABA in synaptic vesicles and provides a potentially useful probe for inhibitory circuits. However, specific pharmacologic agents for VGAT are not available, and VGAT knockout mice are embryonically lethal, thus precluding behavioral studies. We have identified the Drosophila ortholog of the vesicular GABA transporter gene (which we refer to as dVGAT), immunocytologically mapped dVGAT protein expression in the larva and adult and characterized a dVGAT(minos) mutant allele. dVGAT is embryonically lethal and we do not detect residual dVGAT expression, suggesting that it is either a strong hypomorph or a null. To investigate the function of VGAT and GABA signaling in adult visual flight behavior, we have selectively rescued the dVGAT mutant during development. We show that reduced GABA release does not compromise the active optomotor control of wide-field pattern motion. Conversely, reduced dVGAT expression disrupts normal object tracking and figure-ground discrimination. These results demonstrate that visual behaviors are segregated by the level of GABA signaling in flies, and more generally establish dVGAT as a model to study the contribution of GABA release to other complex behaviors.

Drosophila vesicular monoamine transporter mutants can adapt to reduced or eliminated vesicular stores of dopamine and serotonin.

Physiologic and pathogenic changes in amine release induce dramatic behavioral changes, but the underlying cellular mechanisms remain unclear. To investigate these adaptive processes, we have characterized mutations in the Drosophila vesicular monoamine transporter (dVMAT), which is required for the vesicular storage of dopamine, serotonin, and octopamine. dVMAT mutant larvae show reduced locomotion and decreased electrical activity in motoneurons innervating the neuromuscular junction (NMJ) implicating central amines in the regulation of these activities. A parallel increase in evoked glutamate release by the motoneuron is consistent with a homeostatic adaptation at the NMJ. Despite the importance of aminergic signaling for regulating locomotion and other behaviors, adult dVMAT homozygous null mutants survive under conditions of low population density, thus allowing a phenotypic characterization of adult behavior. Homozygous mutant females are sterile and show defects in both egg retention and development; males also show reduced fertility. Homozygotes show an increased attraction to light but are mildly impaired in geotaxis and escape behaviors. In contrast, heterozygous mutants show an exaggerated escape response. Both hetero- and homozygous mutants demonstrate an altered behavioral response to cocaine. dVMAT mutants define potentially adaptive responses to reduced or eliminated aminergic signaling and will be useful to identify the underlying molecular mechanisms.

A glial variant of the vesicular monoamine transporter is required to store histamine in the Drosophila visual system.

Unlike other monoamine neurotransmitters, the mechanism by which the brain's histamine content is regulated remains unclear. In mammals, vesicular monoamine transporters (VMATs) are expressed exclusively in neurons and mediate the storage of histamine and other monoamines. We have studied the visual system of Drosophila melanogaster in which histamine is the primary neurotransmitter released from photoreceptor cells. We report here that a novel mRNA splice variant of Drosophila VMAT (DVMAT-B) is expressed not in neurons but rather in a small subset of glia in the lamina of the fly's optic lobe. Histamine contents are reduced by mutation of dVMAT, but can be partially restored by specifically expressing DVMAT-B in glia. Our results suggest a novel role for a monoamine transporter in glia that may be relevant to histamine homeostasis in other systems.

A screen for neurotransmitter transporters expressed in the visual system of Drosophila melanogaster identifies three novel genes.

The fly eye provides an attractive substrate for genetic studies, and critical transport activities for synaptic transmission and pigment biogenesis in the insect visual system remain unknown. We therefore screened for transporters in Drosophila melanogaster that are down-regulated by genetically ablating the eye. Using a large panel of transporter specific probes on Northern blots, we identified three transcripts that are down-regulated in flies lacking eye tissue. Two of these, CG13794 and CG13795, are part of a previously unknown subfamily of putative solute carriers within the neurotransmitter transporter family. The third, CG4476, is a member of a related subfamily that includes characterized nutrient transporters expressed in the insect gut. Using imprecise excision of a nearby transposable P element, we have generated a series of deletions in the CG4476 gene. In fast phototaxis assays, CG4476 mutants show a decreased behavioral response to light, and the most severe mutant behaves as if it were blind. These data suggest an unforeseen role for the "nutrient amino acid transporter" subfamily in the nervous system, and suggest new models to study transport function using the fly eye.

The Drosophila pigmentation gene pink (p) encodes a homologue of human Hermansky-Pudlak syndrome 5 (HPS5).

Lysosome-related organelles comprise a group of specialized intracellular compartments that include melanosomes and platelet dense granules (in mammals) and eye pigment granules (in insects). In humans, the biogenesis of these organelles is defective in genetic disorders collectively known as Hermansky-Pudlak syndrome (HPS). Patients with HPS-2, and two murine HPS models, carry mutations in genes encoding subunits of adaptor protein (AP)-3. Other genes mutated in rodent models include those encoding VPS33A and Rab38. Orthologs of all of these genes in Drosophila melanogaster belong to the 'granule group' of eye pigmentation genes. Other genes associated with HPS encode subunits of three complexes of unknown function, named biogenesis of lysosome-related organelles complex (BLOC)-1, -2 and -3, for which the Drosophila counterparts had not been characterized. Here, we report that the gene encoding the Drosophila ortholog of the HPS5 subunit of BLOC-2 is identical to the granule group gene pink (p), which was first studied in 1910 but had not been identified at the molecular level. The phenotype of pink mutants was exacerbated by mutations in AP-3 subunits or in the orthologs of VPS33A and Rab38. These results validate D. melanogaster as a genetic model to study the function of the BLOCs.

Transport of polyamines in Drosophila S2 cells: kinetics, pharmacology and dependence on the plasma membrane proton gradient.

Polyamine transport activities have been described in diverse multicellular systems, but their bioenergetic mechanisms and molecular identity remain unclear. In the present paper, we describe a high-affinity spermine/spermidine transport activity expressed in Drosophila S2 cells. Ion-replacement experiments indicate that polyamine uptake across the cell membrane is Na+-, K+-, Cl-- and Ca2+-independent, but pH-sensitive. Additional experiments using ionophores suggest that polyamine uptake may be H+-coupled. Pharmacological experiments show that polyamine uptake in S2 cells is selectively blocked by MGBG {methylglyoxal bis(guanylhydrazone) or 1,1'-[(methylethanediylidine)-dinitrilo]diguanidine} and paraquat (N,N-dimethyl-4,4'-bipyridylium), two known inhibitors of polyamine uptake in mammalian cells. In addition, inhibitors known to block the Slc22 (solute carrier 22) family of organic anion/cation transporters inhibit spermine uptake in S2 cells. These data and the genetic tools available in Drosophila will facilitate the molecular identification and further characterization of this activity.

A splice variant of the Drosophila vesicular monoamine transporter contains a conserved trafficking domain and functions in the storage of dopamine, serotonin, and octopamine.

Vesicular monoamine transporters (VMATs) mediate the transport of dopamine (DA), serotonin (5HT), and other monoamines into secretory vesicles. The regulation of mammalian VMAT and the related vesicular acetylcholine transporter (VAChT) has been proposed to involve membrane trafficking, but the mechanisms remain unclear. To facilitate a genetic analysis of vesicular transporter function and regulation, we have cloned the Drosophila homolog of the vesicular monoamine transporter (dVMAT). We identify two mRNA splice variants (DVMAT-A and B) that differ at their C-terminus, the domain responsible for endocytosis of mammalian VMAT and VAChT. DVMAT-A contains trafficking motifs conserved in mammals but not C. elegans, and internalization assays indicate that the DVMAT-A C-terminus is involved in endocytosis. DVMAT-B contains a divergent C-terminal domain and is less efficiently internalized from the cell surface. Using in vitro transport assays, we show that DVMAT-A recognizes DA, 5HT, octopamine, tyramine, and histamine as substrates, and similar to mammalian VMAT homologs, is inhibited by the drug reserpine and the environmental toxins 2,2,4,5,6-pentachlorobiphenyl and heptachlor. We have developed a specific antiserum to DVMAT-A, and find that it localizes to dopaminergic and serotonergic neurons as well as octopaminergic, type II terminals at the neuromuscular junction. Surprisingly, DVMAT-A is co-expressed at type II terminals with the Drosophila vesicular glutamate transporter. Our data suggest that DVMAT-A functions as a vesicular transporter for DA, 5HT, and octopamine in vivo, and will provide a powerful invertebrate model for the study of transporter trafficking and regulation.