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Sartini S, Lattanzi D, Ambrogini P, Di Palma M, Galati C, Savelli D, Polidori E, Calcabrini C, Rocchi MBL, Sestili P, Cuppini R. Maternal creatine supplementation affects the morpho-functional development of hippocampal neurons in rat offspring. Neuroscience 2015; 312:120-9. [PMID: 26592720 DOI: 10.1016/j.neuroscience.2015.11.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 11/05/2015] [Accepted: 11/10/2015] [Indexed: 12/28/2022]
Abstract
Creatine supplementation has been shown to protect neurons from oxidative damage due to its antioxidant and ergogenic functions. These features have led to the hypothesis of creatine supplementation use during pregnancy as prophylactic treatment to prevent CNS damage, such as hypoxic-ischemic encephalopathy. Unfortunately, very little is known on the effects of creatine supplementation during neuron differentiation, while in vitro studies revealed an influence on neuron excitability, leaving the possibility of creatine supplementation during the CNS development an open question. Using a multiple approach, we studied the hippocampal neuron morphological and functional development in neonatal rats born by dams supplemented with 1% creatine in drinking water during pregnancy. CA1 pyramidal neurons of supplemented newborn rats showed enhanced dendritic tree development, increased LTP maintenance, larger evoked-synaptic responses, and higher intrinsic excitability in comparison to controls. Moreover, a faster repolarizing phase of action potential with the appearance of a hyperpolarization were recorded in neurons of the creatine-treated group. Consistently, CA1 neurons of creatine exposed pups exhibited a higher maximum firing frequency than controls. In summary, we found that creatine supplementation during pregnancy positively affects morphological and electrophysiological development of CA1 neurons in offspring rats, increasing neuronal excitability. Altogether, these findings emphasize the need to evaluate the benefits and the safety of maternal intake of creatine in humans.
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Affiliation(s)
- S Sartini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy.
| | - D Lattanzi
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - P Ambrogini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - M Di Palma
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - C Galati
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - D Savelli
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
| | - E Polidori
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - C Calcabrini
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - M B L Rocchi
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - P Sestili
- University of Urbino Carlo Bo, Dept. of Biomolecular Sciences, via I Maggetti, 26, 61029 Urbino, Italy
| | - R Cuppini
- University of Urbino Carlo Bo, Dept. of Earth, Life and Environmental Sciences, Campus Scientifico "Enrico Mattei", via Ca' le Suore, 2, 61029 Urbino, Italy
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Harris KM, Spacek J, Bell ME, Parker PH, Lindsey LF, Baden AD, Vogelstein JT, Burns R. A resource from 3D electron microscopy of hippocampal neuropil for user training and tool development. Sci Data 2015; 2:150046. [PMID: 26347348 PMCID: PMC4555877 DOI: 10.1038/sdata.2015.46] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 08/12/2015] [Indexed: 12/29/2022] Open
Abstract
Resurgent interest in synaptic circuitry and plasticity has emphasized the importance of 3D reconstruction from serial section electron microscopy (3DEM). Three volumes of hippocampal CA1 neuropil from adult rat were imaged at X-Y resolution of ~2 nm on serial sections of ~50-60 nm thickness. These are the first densely reconstructed hippocampal volumes. All axons, dendrites, glia, and synapses were reconstructed in a cube (~10 μm(3)) surrounding a large dendritic spine, a cylinder (~43 μm(3)) surrounding an oblique dendritic segment (3.4 μm long), and a parallelepiped (~178 μm(3)) surrounding an apical dendritic segment (4.9 μm long). The data provide standards for identifying ultrastructural objects in 3DEM, realistic reconstructions for modeling biophysical properties of synaptic transmission, and a test bed for enhancing reconstruction tools. Representative synapses are quantified from varying section planes, and microtubules, polyribosomes, smooth endoplasmic reticulum, and endosomes are identified and reconstructed in a subset of dendrites. The original images, traces, and Reconstruct software and files are freely available and visualized at the Open Connectome Project (Data Citation 1).
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Affiliation(s)
- Kristen M Harris
- Department of Neuroscience, Center for Learning and Memory, Institute for Neuroscience, University of Texas at Austin, 1 University Station C7000 , Austin, Texas 78712, USA
| | - Josef Spacek
- Department of Pathology, Charles University at Prague, Faculty of Medicine , 500 35 Hradec Kralove, Czech Republic
| | - Maria Elizabeth Bell
- Department of Neuroscience, Center for Learning and Memory, Institute for Neuroscience, University of Texas at Austin, 1 University Station C7000 , Austin, Texas 78712, USA
| | - Patrick H Parker
- Department of Neuroscience, Center for Learning and Memory, Institute for Neuroscience, University of Texas at Austin, 1 University Station C7000 , Austin, Texas 78712, USA
| | - Laurence F Lindsey
- Department of Neuroscience, Center for Learning and Memory, Institute for Neuroscience, University of Texas at Austin, 1 University Station C7000 , Austin, Texas 78712, USA
| | - Alexander D Baden
- Department of Computer Science, Institute for Data Intensive Science and Engineering, Johns Hopkins University, 160 Malone Hall, 3400 N. Charles St. , Baltimore, Maryland 21218, USA
| | - Joshua T Vogelstein
- Department of Biomedical Engineering, Institute for Computational Medicine, Johns Hopkins University, Clark Hall Room 317C, 3400 N. Charles St. , Baltimore, Maryland 21218, USA
| | - Randal Burns
- Department of Computer Science, Institute for Data Intensive Science and Engineering, Johns Hopkins University, 160 Malone Hall, 3400 N. Charles St. , Baltimore, Maryland 21218, USA
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Structural Components of Synaptic Plasticity and Memory Consolidation. Cold Spring Harb Perspect Biol 2015; 7:a021758. [PMID: 26134321 DOI: 10.1101/cshperspect.a021758] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Consolidation of implicit memory in the invertebrate Aplysia and explicit memory in the mammalian hippocampus are associated with remodeling and growth of preexisting synapses and the formation of new synapses. Here, we compare and contrast structural components of the synaptic plasticity that underlies these two distinct forms of memory. In both cases, the structural changes involve time-dependent processes. Thus, some modifications are transient and may contribute to early formative stages of long-term memory, whereas others are more stable, longer lasting, and likely to confer persistence to memory storage. In addition, we explore the possibility that trans-synaptic signaling mechanisms governing de novo synapse formation during development can be reused in the adult for the purposes of structural synaptic plasticity and memory storage. Finally, we discuss how these mechanisms set in motion structural rearrangements that prepare a synapse to strengthen the same memory and, perhaps, to allow it to take part in other memories as a basis for understanding how their anatomical representation results in the enhanced expression and storage of memories in the brain.
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Cao G, Harris KM. Augmenting saturated LTP by broadly spaced episodes of theta-burst stimulation in hippocampal area CA1 of adult rats and mice. J Neurophysiol 2014; 112:1916-24. [PMID: 25057146 DOI: 10.1152/jn.00297.2014] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Hippocampal long-term potentiation (LTP) is a model system for studying cellular mechanisms of learning and memory. Recent interest in mechanisms underlying the advantage of spaced over massed learning has prompted investigation into the effects of distributed episodes of LTP induction. The amount of LTP induced in hippocampal area CA1 by one train (1T) of theta-burst stimulation (TBS) in young Sprague-Dawley rats was further enhanced by additional bouts of 1T given at 1-h intervals. However, in young Long-Evans (LE) rats, 1T did not initially saturate LTP. Instead, a stronger LTP induction paradigm using eight trains of TBS (8T) induced saturated LTP in hippocampal slices from both young and adult LE rats as well as adult mice. The saturated LTP induced by 8T could be augmented by another episode of 8T following an interval of at least 90 min. The success rate across animals and slices in augmenting LTP by an additional episode of 8T increased significantly with longer intervals between the first and last episodes, ranging from 0% at 30- and 60-min intervals to 13-66% at 90- to 180-min intervals to 90-100% at 240-min intervals. Augmentation above initially saturated LTP was blocked by the N-methyl-D-aspartate (NMDA) glutamate receptor antagonist D-2-amino-5-phosphonovaleric acid (D-APV). These findings suggest that the strength of induction and interval between episodes of TBS, as well as the strain and age of the animal, are important components in the augmentation of LTP.
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Affiliation(s)
- Guan Cao
- The Center for Learning and Memory, University of Texas at Austin, Austin, Texas
| | - Kristen M Harris
- The Center for Learning and Memory, University of Texas at Austin, Austin, Texas
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