Dr Volko Straub

Tel: +44  (0)116 252 3090       Email:  vs64@le.ac.uk


Interests and techniques

My research is broadly centred on the study of neuromodulation, short- and long-term changes in neuronal networks and behavioural plasticity with a specific focus on the role of serotonin and nitric oxide. In this work, I try to integrate the use of both invertebrate (snails/slugs) and vertebrate model systems (dissociated cell and organotypic rat cortical cultures, acute brain slices) and use a range of techniques ranging from behavioural studies to electrophysiological, functional calcium imaging, immunohistochemistry and molecular methods.

Current main research projects are focused on:

Role of serotonergic signalling in cortical development

Cortical CultureSerotonin is an important neuromodulatory signalling molecule in the central nervous system that has been linked to a range of conditions including depression, autism, schizophrenia and aggressive behaviour. Recent evidence suggests that some of the links are due to effects of serotonin during development of the central nervous system. In order to gain a better understanding of serotonin in cortical development, we have started recently to study the effects of serotonergic signalling on neurite growth and synapse formation in cortical cell and organotypic cultures (Baliga et al, 2015; Baily et al, 2017; Picture: Rat primary cortical cell culture transfected with GFP [green] and stained for MAP2 [red]. The DNA dye Hoechst was used to visualise nuclei [blue]).

Integration of sensory signalling pathways, learning and decision making in snails

Snail Food Preference LearningGastropods constitute a significant agricultural and horticultural pest around the world. This is in part due to their ability to rapidly adapt their food preference (Peschel et al., 1996), which makes them highly adaptive to changes in their environment and also very damaging as once they have 'acquired a taste' for a specific crop, they will feed selectively on that food source. This adaptive and flexible feeding strategy could also lead to active avoidance of molluscicide baits. Therefore, we have started a project to study the neuronal mechanisms that underlie the integration of chemosensory/olfactory signals (indicating the presence of a potential food source in the environment) and internal reward signals (providing feedback about the nutritional status of a food source), and how they interact to modify decision making. This project may provide important leads for the development of novel control strategies for gastropod pests with potentially less environmental impact than the common current practice of large scale molluscicide use.


Additional/previous research projects

Serotonergic modulation of cellular properties

Serotonin is a known modulator of intrinsic properties of both molluscan and mammalian neurons. I have previously shown that serotonin can induce conditional bursting and enhance post inhibitory rebound properties in the B4 buccal neuron of Lymnaea stagnalis (Straub & Benjamin, 2001). It also increases B4 excitability and more recently we have been studying its effects on specific voltage-gated potassium currents. We also carried out related studies in mammalian cortical neurons (Bammann et al, 2012).

Interactions between serotonin and nitric oxide

Colocalisation of serotonin and nitric oxide synthase has been described in various neurons including the Lymnaea cerebral giant cell (CGC) that provides the serotonergic input to the B4 neuron. Studying the effects of nitrergic signalling on B4 neurons revealed that nitric oxide enhances the postsynaptic effect of serotonin (Straub et al, 2007; Straub et al, 2013). We also explored whether nitric oxide can also modulate serotonergic responses in mammalian cortical neurons (Bammann et al, 2013; Straub et al, 2014).

Nitric oxide, neuritogenesis and synapse formation

Long-term memory formation involves theVolko Straub Research Page Image 2 remodeling of existing synapses and the creation of novel synapses. These processes require neurons to undergo morphological changes, i.e. sprouting of new growth cones; extension and/or retraction of spines and processes; formation or removal of synapses. Previous work has demonstrated that nitric oxide plays a significant role in learning and memory formation in Lymnaea (Korneev et al, 2002, 2005, Kemenes et al, 2006), similar to its role in other vertebrate and invertebrate species. In order to study whether endogenous nitric oxide can affect neuronal growth and synapse formation in adult neurons, we studied the effect of nitric oxide signaling on neuronal regeneration and synaptic re-modeling following axonal injury of identified Lymnaea B1 and B2 neurons. This enabled us to demonstrate that nitric oxide significantly modulates both neuronal growth and synaptic re-modelling (Cooke et al, 2013).

Identification and characterisation of purinergic P2X receptors in invertebrates
(collaboration with S Ennion)

ATP sensitive purine receptors have been characterised extensively in vertebrates, but relatively little work had been conducted in invertebrate species. We cloned and characterised P2X receptors from Lymnaea (Bavan et al, 20111, 2012) and the tardigrade Hypsibius dujardini (Bavan et al, 2009).



Arundell M, Patel BA, Straub V, Allen MC, Janse C, O’Hare D, Parker K, Gard PR, Yeoman MS (2006) Effects of age on feeding behavior and chemosensory processing in the pond snail, Lymnaea stagnalis. Neurobiol Aging 27:1880–1891.

Baily Z, Mackay C, Straub V (2017) Effects of 5HT1A and 5HT7 receptor signalling on development of rat cortical neurons. BNA 2017 Festiv Neurosci Abstr Book: P-M150.

Baliga R, Lee A, Straub V (2015) Chronic exposure to 5HT and 5HT1 agonist 8-OH-DPAT affects development of rat cortical neurons in cell culture. BNA 2015 Festiv Neurosci Abstr Book: P3-NaN-8.

Bammann, R, Hartell, N, Straub, VA (2013) Nitric oxide modulation of intrinsic properties of cultured cortical neurons. In: British Neurosci. Assoc. Abstr., pp 720. London.

Bammann, RR, Tilston, M, Satchell, F, Hartell, NA, Straub, VA (2012) Serotonin Modulates The Intrinsic Cellular Properties Of Cultured Cortical Neurons. In: FENS Abstract, pp 5.1. Barcelona.

Bavan S, Farmer L, Singh SK, Straub VA, Guerrero FD, Ennion SJ (2011) The penultimate arginine of the carboxy terminus determines slow desensitization in a P2X receptor from the cattle tick Boophilus microplus. Mol Pharmacol (http://molpharm.aspetjournals.org/content/early/2011/01/06/mol.110.070037.abstract)

Bavan S, Straub VA, Blaxter ML, Ennion SJ (2009) A P2X receptor from the tardigrade species Hypsibius dujardini with fast kinetics and sensitivity to zinc and copper. BMC Evol Biol 9:17.

Bavan S, Straub VA, Webb TE, Ennion SJ (2012) Cloning and characterization of a P2X receptor expressed in the central nervous system of Lymnaea stagnalis. PloS One 7:e50487.

Cooke RM, Mistry R, Challiss RAJ, Straub VA (2013) Nitric Oxide Synthesis and cGMP Production Is Important for Neurite Growth and Synapse Remodeling after Axotomy. J Neurosci 33:5626–5637.

Cooke RM, Straub VA (2008) Nitric oxide and neuritogenesis of isolated central neurons in Lymnaea stagnalis. In: FENS Abstr., pp 142.3.

Cooke R. M., Straub V. A. (2010) Nitric oxide affects injury-induced neuritogenesis and synaptogenesis. In: FENS Abstr., pp 160.3. Amsterdam. Available at: http://fens2010.neurosciences.asso.fr/abstracts/R6/A160_3.html

Feng Z-P, Zhang Z, van Kesteren RE, Straub VA, van Nierop P, Jin K, Nejatbakhsh N, Goldberg JI, Spencer GE, Yeoman MS, Wildering W, Coorssen JR, Croll RP, Buck LT, Syed NI, Smit AB (2009) Transcriptome analysis of the central nervous system of the mollusc Lymnaea stagnalis. BMC Genomics 10:451.

Kemenes I, Straub VA, Nikitin ES, Staras K, O’Shea M, Kemenes G, Benjamin PR (2006) Role of delayed nonsynaptic neuronal plasticity in long-term associative memory. Curr Biol CB 16:1269–1279.

Korneev SA, Kemenes I, Straub V, Staras K, Korneeva EI, Kemenes G, Benjamin PR, O’Shea M (2002) Suppression of nitric oxide (NO)-dependent behavior by double-stranded RNA-mediated silencing of a neuronal NO synthase gene. J Neurosci 22:RC227.

Korneev SA, Straub V, Kemenes I, Korneeva EI, Ott SR, Benjamin PR, O’Shea M (2005) Timed and targeted differential regulation of nitric oxide synthase (NOS) and anti-NOS genes by reward conditioning leading to long-term memory formation. J Neurosci 25:1188–1192.

Okunoren-Oyekenu Y, Straub V (2014) Effects Of Nitric Oxide Signalling On Growth And Health Of Cortical Cultures. In. London.

Park JH, Straub VA, O’Shea M (1998) Anterograde signaling by nitric oxide: characterization and in vitro reconstitution of an identified nitrergic synapse. J Neurosci 18:5463–5476.

Perry SJ, Straub VA, Kemenes G, Santama N, Worster BM, Burke JF, Benjamin PR (1998) Neural modulation of gut motility by myomodulin peptides and acetylcholine in the snail Lymnaea. J Neurophysiol 79:2460–2474.

Perry SJ, Straub VA, Schofield MG, Burke JF, Benjamin PR (2001) Neuronal expression of an FMRFamide-gated Na+ channel and its modulation by acid pH. J Neurosci Off J Soc Neurosci 21:5559–5567.

Peschel M, Straub V, Teyke T (1996) Consequences of food-attraction conditioning in Helix: a behavioral and electrophysiological study. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 178:317–327.

Ribeiro M, Straub VA, Schofield M, Picot J, Benjamin PR, O’Shea M, Korneev SA (2008) Characterization of NO-sensitive guanylyl cyclase: expression in an identified interneuron involved in NO-cGMP-dependent memory formation. Eur J Neurosci 28:1157–1165.

Straub VA (2009) Central Pattern Generator. In: Encyclopedia of Neuroscience (Binder MD, Hirokawa N, Windhorst U, eds). Springer. Available at: http://dx.doi.org/10.1007/978-3-540-29678-2

Straub VA, Benjamin PR (2001) Extrinsic modulation and motor pattern generation in a feeding network: a cellular study. J Neurosci 21:1767–1778.

Straub VA, Grant J, O’Shea M, Benjamin PR (2007) Modulation of serotonergic neurotransmission by nitric oxide. J Neurophysiol 97:1088–1099.

Straub VA, Kemenes I, O’Shea M, Benjamin PR (2006) Associative memory stored by functional novel pathway rather than modifications of preexisting neuronal pathways. J Neurosci 26:4139–4146.

Straub VA, Staras K, Kemenes G, Benjamin PR (2002) Endogenous and network properties of Lymnaea feeding central pattern generator interneurons. J Neurophysiol 88:1569–1583.

Straub VA, Styles BJ, Ireland JS, O’Shea M, Benjamin PR (2004) Central localization of plasticity involved in appetitive conditioning in Lymnaea. Learn Mem Cold Spring Harb N 11:787–793.

Straub V, Bammann R, Hartell, N (2014) Differential effects of serotonin and nitric oxide on the intrinsic cellular properties of distinct populations of cultured cortical neurons. FENS Abstr.. Milano: FENS. (http://fens2014.meetingxpert.net/FENS_427/poster_102359/program.aspx).

Straub V, Okunoren-Oyekenu Y (2015) Effects of nitric oxide on the development of cortical cultures. BNA 2015 Festiv Neurosci Abstr Book (https://www.bna.org.uk/media/resources/files/BNA2015-Abstract-Book.pdf).

Straub, VA, Pryor, A, Őzkaya, Ő, Rosato, E (2013) Nitric oxide modulation of cAMP-gated ion channel is independent of protein kinase G and phosphodiesterase activity. In: British Neurosci. Assoc. Abstr., pp 722. London.

Vavoulis DV, Straub VA, Kemenes I, Kemenes G, Feng J, Benjamin PR (2007) Dynamic control of a central pattern generator circuit: a computational model of the snail feeding network. Eur J Neurosci 25:2805–2818.

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