\begin{table}
\caption{Fragile X mouse synaptic plasticity phenotypes}
\label{table_1}
\begin{tabular}{lllll}
Category & Region & Fragile X Mouse Phenotype & Age & References \\

mGluR LTD & hippocampus & enhanced & P25--30 & \cite{Huber_2002, Hou_2006, Bhattacharya_2012, Michalon_2012} \\
mGluR LTD & hippocampus & does not require new protein synthesis & 4--12 wk & \cite{Nosyreva_Huber_2006, Hou_2006, Zang_2009} \\
mGluR LTD & hippocampus & enhanced and not PS-dependent & P35--42 & \cite{Iliff_2012} \\
mGluR LTD & cerebellum & enhanced & 3--7 wk & \cite{Koekkoek_2005} \\
mGluR LTD & hippocampus & enhanced and does not require new protein synthesis & 3--7 wk & \cite{Volk_2007} \\

LTP & hippocampus & NONE & 20--26 wk; 8--10 wk; 3--12 month & \cite{Godfraind_1996, Li_2002, Larson_2005} \\
L-LTP & hippocampus & NONE & 5--7 wk; 2--4 month & \cite{Paradee_1999, Zhang_2009} \\
LTP & hippocampus & deficient & 2 wk; 6--8 wk & \cite{Hu_2008, Shang_2009} \\
LTP & hippocampus & deficient with weak stimulus; normal with strong stimulus & 2--3 month & \cite{Lauterborn_2007} \\
LTP & hippocampus & enhanced B-adrenergic-facilitated heterosynaptic LTP (PS-dependent) & 3--4 month & \cite{Connor_2011} \\

LTP priming & hippocampus & does not require new protein synthesis (mGluR-dependent) & 6--10 wk & \cite{Auerbach_Bear_2010} \\

LTP & anterior cingulate ctx & deficient & 6--8 wk & \cite{Zhao_2005, Xu_2012} \\
LTP & anterior cingulate ctx & impaired facilitation of LTP by 5-HT2AR agonist & 6--8 wk & \cite{Xu_2012} \\

LTP & somatosensory, temporal ctx & deficient & 8--10 wk; 3 month & \cite{Li_2002, Hayashi_2007} \\
LTP & somatosensory ctx & delayed window for plasticity & P3--10 & \cite{Harlow_2010} \\
LTP & visual ctx & deficient (mGluR-dependent) & P13--25 & \cite{Wilson_Cox_2007} \\
LTP & anterior piriform ctx & deficient in aged mice; normal in 3--6 mo mice & 6--18 month & \cite{Larson_2005} \\
LTP & amygdala & impaired (mGluR-dependent) & 6--8 wk; 3.5--6 mo & \cite{Zhao_2005, Suvrathan_2010} \\

STD-LTP & somatosensory ctx & deficient with weak stimulus & P10--18 & \cite{Desai_2006} \\
STD-LTP & prefrontal ctx & deficient with weak stimulus; normal with strong stimulus & P14--23 & \cite{Meredith_2007} \\

homeostasis & hippocampus & deficient translation-dependent scaling & P6--7 slice culture & \cite{Soden_Chen_2010} \\
homeostasis & hippocampus & normal transcription-dependent scaling & P6--7 slice culture & \cite{Soden_Chen_2010} \\

experience-dependent & visual ctx (in vivo) & altered ocular dominance plasticity & LTD & \cite{Dolen_2007} \\
experience-dependent & somatosensory ctx & deficient experience-dependent plasticity (induced by whisker trimming) & LTD & \cite{Bureau_2008} \\

\end{tabular}
\end{table}

\textbf{LEGEND:} Fragile X mouse models have multiple altered forms of synaptic plasticity across multiple brain regions. The majority of phenotypes were assessed in the \textit{Fmr1} KO mouse which lacks FMRP. *Assessed using a CGG knock-in mouse which models FX premutation. **Assessed using an FMRP point mutant mouse with disrupted FMRP--mRNA binding.

LTD (Figure~\ref{fig:figure_1}). However, while the magnitude of L-LTP is unchanged, it is possible that L-LTP is qualitatively different in its requirement for new protein synthesis when FMRP is absent, as is the case for mGluR-LTD (and LTP priming, see below). Therefore, it will be important to test the protein synthesis-dependency of L-LTP in \textit{Fmr1} KO mice to show that FMRP truly does not play a role in regulating the persistence of LTP.

Alternatively, FMRP may be required for the regulation of local but not somatic translation in the context of L-LTP (Figure~\ref{fig:figure_1}). L-LTP is traditionally induced by multiple trains of high frequency tetanus or theta burst stimulation, protocols that rely on cell-wide transcription and translation \cite{63,64,65}. L-LTP was characterized in the \textit{Fmr1} KO mouse using these classical paradigms \cite{61,62}. However, using a less intense induction protocol