Marie, Bruno, PhD

Adjunct Professor

Associate Investigator of Institute of Neurobiology

Dr. Bruno Marie

Contact Info

  • Institute of Neurobiology, Lab 314
  • 787-721-4149

Research Interests

My laboratory is using the powerful tools of Drosophila genetics to answer basic questions regarding synapse function and development.

1- Molecular mechanisms underlying rapid activity-dependent synaptic plasticity

For decades synaptic plasticity has been associated with fundamental brain functions such as learning and memory. After repeated stimulation, the neuromuscular junction (NMJ) undergoes morphological and electrophysiological changes defined as rapid activity-dependent synaptic plasticity. Such an event requires WNT, a signaling molecule that has been associated with schizophrenia and Alzheimer’s disease. We are aiming at isolating and characterizing the molecular mechanisms downstream of the Wnt signaling that are involved in rapid activity-dependent synaptic plasticity.

2- The molecular control of Synaptic Homeostasis

My laboratory is also exploring how homeostatic signaling can modulate synaptic release. Homeostasis is a form of feedback regulation that precisely maintains the function of a system at a set point level of activity. Within the nervous system, homeostatic signaling systems are thought to constrain plasticity to ensure neural activity will remain stable over time. As such, homeostatic mechanisms are thought to be the mechanisms that prevent the nervous system to fall into chaos and impairment of such mechanisms has been hypothesized to be responsible for epilepsy. However, the molecular mechanisms of homeostasis in the nervous system are virtually unknown. Homeostatic control of neuronal activity has been shown to occur in the CNS and PNS of both vertebrates and invertebrates following perturbation of neuron or muscle excitability. Homeostatic regulation of synaptic strength has been demonstrated at the Drosophila (NMJ). The Drosophila NMJ is a glutamatergic synapse. Manipulations that decrease the sensitivity of postsynaptic glutamate receptors (GluR), cause a compensatory, homeostatic increase in presynaptic neurotransmitter release (see diagram).  This increase in presynaptic neurotransmitter release precisely counteracts the decrease in postsynaptic receptor sensitivity allowing normal muscle contraction.

We are now attempting to characterize molecules, ranging from transcription factor to ion channel, necessary to synaptic compensation.

3- Physiological and molecular consequences of environmental change on the nervous system of Drosophila melanogaster.
This project assesses the consequences of environmental change on synaptic development, function and plasticity in Drosophila.  We first focused on the effect of temperature on synaptic development and determined that there is a temperature-dependence of synaptic growth (Synapses from animals grown at 30°C are twice as big as synapses from animals grown at 15°C). We are now trying to identify and characterize the molecular mechanisms underlying this temperature-dependence of synaptic growth.The second aspect of this research consists in asking whether the contaminants found in Puerto Rican rivers can affect the synaptic development, function or plasticity of Drosophila.

Present Funding

NIH R21, NSF CREST

Selected Publications:

  • Maldonado-Díaz C*, Vazquez M, Marie B (2021) A comparison of three different methods of eliciting rapid activity-dependent synaptic plasticity at the Drosophila NMJ. PLoS One. 2021 Nov 30;16(11):e0260553. doi: 10.1371/journal.pone.0260553. (pp.1-22) PMID: 34847197; PMCID: PMC8631638.
  • Reyes-Maldonado R*, Marie B, Ramirez A (2021) Rearing methods and life cycle characteristics of Chronomus sp. Florida (Chironomidae: Diptera): A rapid-developing species for laboratory studies. PLoS One Feb 22; 16(2):e0247382. doi: 10.1371/journal.pone.0247382. eCollection 2021 PMID: 33617595
  • Colón-Cruz L*, Rodríguez Morales R*, Santana-Cruz A*, Cantres-Velez J, Torrado-Tapias A, Sin SJ, Yudowski G, Kensler R, Marie B, Burgess SM, REanaud O, Varshney GK, Behra M (2021) Cnr2 is important for ribbon synapse maturation and function in hair cells and photoreceptors. Front Mol Neurosci Apr 20 14:624265. doi: 10.3389/fnmol.2021.624265. eCollection 2021.PMID: 33958989
  • Alicea D, Perez M, Maldonado C*, Dominicci-Cotto C*, Marie B (2017) Cortactin is a regulator of activity-dependent synaptic plasticity controlled by wingless. J Neurosci 37(8):2203-2215
  • West RJ H, Lu Y, Marie B, Gao FB, Sweeney ST (2015) Rab8, POSH, and TAK1 regulate synaptic growth in a Drosophila model of frontotemporal dementia. J Cell Biol, 208(7):931-947.
  • Pézier A, Jezzini S, Marie B, and Blagburn J (2014) Engrailed alters the specificity of synaptic connections of Drosophila auditory neurons with the giant fiber. Journal of Neuroscience. Aug 27;34(35):11691-704. doi: 10.1523/JNEUROSCI.1939-14.2014.
  • Maldonado C, Alicea D, Gonzalez M, Bykhovskaia M, Marie B (2013) Adar is essential for optimal presynaptic function. Molecular and Cellular Neuroscience Jan;52:173-80. doi: 10.1016/j.mcn.2012.10.009.
  • Marie B, Pym E, Bergquist S, Davis GW (2010) Synaptic homeostasis is consolidated by the cell fate gene gooseberry, a Drosophila pax3/7 homolog. J Neurosci 30(24):8071-8082.
  • Booth D, Marie B, Domenici P, Blagburn JM, Bacon JP (2009) Transcriptional control of behavior: engrailed knock-out changes cockroach escape trajectories. J Neurosci. Jun 3;29(22):7181-90.
  • Marie B, Sweeney ST, Poskanzer KE, Roos J, Kelly RB, Davis GW (2004) Dapl60/intersectin scaffolds the periactive zone to achieve high-fidelity endocytosis and normal synaptic growth. Neuron. 43: 207-219.
  • Marie B, Blagburn JM (2003) Differential roles of Engrailed paralogs in determining sensory axon guidance and synaptic target recognition. Journal of Neuroscience 23: 7854-7862.
  • Soto I, Marie B, Baro DJ, Blanco RE (2003) FGF-2 modulates the expression and distribution of GAP-43 in frog retinal ganglion cells after optic nerve injury. Journal of Neuroscience Research 73: 507-517.
  • Marie B, Cruz-Orengo L and Blagburn JM (2002) Persistent Engrailed expression is required to determine sensory axon trajectory, branching, and target choice. Journal of Neuroscience 22: 832-841.
  • Marie B, Bacon JP and Blagburn JM (2000). Double-stranded RNA interference shows that Engrailed controls the synaptic specificity of identified sensory neurons. Current Biology 10: 289-292.
  •  Marie B, Bacon JP (2000) Two engrailed-related genes in the cockroach: cloning, phylogenetic analysis, expression and isolation of spliced variants. Development, Genes and Evolution 210: 436-448.