Excessive Daytime Sleepiness (not Narcolepsy) AT WHAT AGE DO CHILDREN DEMONSTRATE AN UNDERSTANDING OF THE VOCABULARY ASSOCIATED WITH SLEEP? B. Ludwig , H. Heussler, S. Smith. University of Queensland, Brisbane, Australia Introduction: When hypersomnolence is suspected, children and their parents are routinely screened using one of a number of available surveys. The vocabulary used in these surveys is sleep-specific and possibly adult- oriented, thus it is questionable whether younger children really do comprehend the intent of the questions. The present study aimed to identify children's understanding of the terminology utilised in sleep surveys, particularly the Paediatric Daytime Sleepiness Scale (PDSS). The PDSS was originally developed by Drake, Nickel, Burduvali, Roth, Jefferson, and Badia (2003) as a measure of sleepiness for 11-15 year olds. Nixon, Wawruszak, Verginis, and Davey (2006) then evaluated the use of the PDSS in elementary school children (5-12.9 years). Neither study commented on the sleep vocabulary used within the scale nor whether additional ex- planations of each question were given to the children by adults admin- istering the scale. Materials and methods: This school-based community study surveyed all students from a regional primary school, aged 4 through to 12 years, their parents/guardians, and their teachers using the Paediatric Daytime Sleepiness Scale (PDSS) and a background information survey completed by a carer. 52 percent of the 727 student and carer surveys distributed were returned; and 67 percent of the teachers responded. Prior to commencing the PDSS, each child was asked the meaning of seven key words used in the questions: drowsy, sleepy, alert, awakened, tired, fatigued, and awake. Their responses were recorded/scribed by their carer on the front page of the child's questionnaire. This study utilised these qualitative data, i.e. the actual definition of each word tendered by each child. Results: The final vocabulary sample consisted of word definitions from 325 children. The qualitative data yielded perceptions reflective of the developmental expressive vocabulary ability of each child: younger chil- dren gave more literal and concrete definitions, often with an example from their own life, whilst older children were more global in their choice of vocabulary to define each word. Interestingly, the oldest groups (10,11 and 12 year olds) frequently chose more abstract words when generating their definitions. The word fatigued, for example, was the most challenging for children to define, with only 2% of 4-5 year olds (N ¼ 51) through to only 30% of 11-12 year olds (N ¼ 40) able to give an approximate definition through inclusion of words such as exhausted, weary, or very tired in their definition. Of the other six words included in this survey, drowsy, alert, and awakened were similarly challenging for the children to define. Conclusions: Sleepiness surveys are frequently utilised by professionals in various capacities, including in research and prior to clinical sleep studies, to gain insight into a child's own perception of their hypersomnolence. However, the vocabulary in these surveys is sleep-specific, and in the case of the PDSS as investigated through this study, utilises vocabulary not in general use by children. Giving a brief definition of these key words prior to administering the survey may yield a more accurate reflection of a child's sleep and daytime behaviours. Acknowledgements: Thanks to students of Rangeville State School, Queensland. Basic Research ACTIVATION DURING SLEEP AND WAKING OF THE SUPRAMAMMILLARY NUCLEUS-DENTATE GYRUS PATHWAY BY OPTOGENETIC INDUCES AN INCREASE IN THETA AND GAMMA POWER P.-H. Luppi 1 , F. Billwiller 1 , M. Esclapez 2 . 1 Sleep Team, UMR 5292 CNRS/ U1028 INSERM, University of Lyon, Lyon, France; 2 UMR 1106 INSERM, Aix- Marseille Universit e, Institut de Neurosciences des Syst emeseINS, Marseille, France Introduction: Recent studies strongly support a role of the two states of sleep, slow wave (SWS) and paradoxical sleep (PS) in learning and memory consolidation. However, the mechanisms underlying the beneficial effect of both states of sleep in learning and memory have not yet been identified. To this aim, we recently identified at cellular level the pop- ulations of cortical neurons activated and displaying plasticity during PS hypersomnia by means of functional neuroanatomy. Such mapping clearly showed for the first time that only a small number of limbic structures are activated during PS in contrast to waking. Among them, the dentate gyrus (DG) is the only cortical region that display more activated neurons during PS hypersomnia than during waking (Renouard et al., 2015). Further, combining retrograde tracing, neurotoxic lesion and FOS immunostaining, we showed that neurons from the lateral part of the supramammillary nucleus (SuML) projecting to the DG, are responsible for the activation of DG granule cells during PS. These surprising results pointed out for the first time that the SuML/DG pathway activates DG granule cells specifically during PS. Materials and methods: To further study this pathway, we transfected channelrhodopsin or Halorhodopsin in the glutamatergic neurons of the SumL in vGlut2Cre mice using Cre dependent AAVs. Control vGLUT2-Cre mice received the viral vector containing only the fluorescent reporter EYFP. Mice were implanted with EEG and EMG electrodes and a custom made optrode was placed unilaterally in the dorsal DG. Optical stimula- tions were applied at 20 Hz during 10 s during waking, SWS and PS. The last day, the mice were stimulated 15 min and perfused 90 min later. Results: Optogenetic stimulation during SWS but not PS induced waking in ChR2 but not in control mice. Optogenetic stimulations during SWS and waking induced an increase in muscle activity only in ChR2 mice. Stimu- lations during the three states induced a significant increase in the theta/ delta power ratio and in gamma power in the DG LFP. Stimulations during PS induced an increase of the theta peak frequency. Stimulation before perfusion induced a strong and significant increase in the number of Fos- labeled neurons in the DG region ventral to optic fiber only in ChR2mice. Inhibition of DG fibers in mice using halorhodopsin induced no effect on the state of the animal nor on the LFP. Conclusions: Our results indicate that the SumL/DG pathway increases theta power and frequency. Since our previous results indicate that the pathway is mainly active during PS, it suggests that it would be responsible for the increase in theta and gamma power occurring specifically in the DG during PS reported previously (Montgomery et al., 2008). Additional ex- periments are now necessary to determine the function of the activation of the SumL/DG during PS in particular with regard to learning and memory. Insomnia THE PARADOX OF CHANGING THE SLEEP ARCHITECTURE IN ADMINISTRATION OF HYPNOTICS V. Cojocaru 1 , M. Bodnari 2 , A. Lupus ¸ or 2 , V. Vovc 3 . 1 “Nicolae Testemitanu” State University of Medicine and Pharmacy, Republic of Moldova; 2 “Nicolae Testemitanu” State University of Medicine and Pharmacy, Republic of Moldova; 3 State University of Medicine and Pharmacy “Nicolae Testemitanu”, Chis ¸ in au, Republic of Moldova Introduction: According to unofficial data, in the Republic of Moldova, hypnotics are the first line treatment for insomnia. According to literature data, these drugs alter the normal sleep structure. Thus, hypnotic-induced sleep will have lower latency and it will be longer, but with altered structure. Moreover, hypnotics cause addiction, tolerance and do not treat the causes of insomnia. Materials and methods: A series of cases have been analyzed. From the database of the Center of Somnology within the Institute of Neurology and Neurosurgery, 11 patients with insomnia were researched with cardiore- spiratory polymorphism with neuroport, who had already administered hypnotics from the benzodiazepines group and/or non-benzodiazepines, by the time they addressed. Results: According to hypograms, sleep efficiency was down to 64% of patients and sleep latency went up to 50%. At the same time, 50% of patients suffered an increase in phases 1 and 2 (NREM), and 91% had the third phase of NREM sleep diminished compared to normal; half of patients recorded a sleep with rapid eye movement(REM) within the normal range. Hypnogram analysis revealed changes in the ratio be- tween sleep stages: superficial sleep was increased and the slow wave sleep, diminished. Reduced sleep efficacy and increased sleep latency denote the low efficacy of hypnotics in the treatment of insomnia of the studied cases. Abstracts / Sleep Medicine 40 (2017) e186ee363 e201