  Let $R$ be a commutative $\mathbb{Z}[1/p]$-algebra, let $m \leq n$ be
positive integers, and let $G_n=\text{GL}_n(F)$ and $G_m=\text{GL}_m(F)$ where
$F$ is a $p$-adic field. The Weil representation is the smooth $R[G_n\times
G_m]$-module $C_c^{\infty}(\text{Mat}_{n\times m}(F),R)$ with the action
induced by matrix multiplication. When $R=\mathbb{C}$ or is any algebraically
closed field of banal characteristic compared to $G_n$ and $G_m$, the local
theta correspondence holds by the work of Howe and M\'inguez. At the level of
supercuspidal support, we interpret the theta correspondence as a morphism of
varieties $\theta_R$, which we describe as an explicit closed immersion. For
arbitrary $R$, we construct a canonical ring homomorphism $\theta^\#_{R} :
\mathfrak{Z}_{R}(G_n)\to \mathfrak{Z}_{R}(G_m)$ that controls the action of the
center $\mathfrak{Z}_{R}(G_n)$ of the category of smooth $R[G_n]$-modules on
the Weil representation. We use the rank filtration of the Weil representation
to first obtain $\theta_{\mathbb{Z}[1/p]}^\#$, then obtain $\theta^\#_R$ for
arbitrary $R$ by proving $\mathfrak{Z}_R(G_n)$ is compatible with scalar
extension. In particular, the map $\text{Spec}(\mathfrak{Z}_R(G_m))\to
\text{Spec}(\mathfrak{Z}_R(G_n))$ induced by $\theta_R^\#$ recovers $\theta_R$
in the $R=\mathbb{C}$ case and in the banal case. We use gamma factors to prove
$\theta_R^\#$ is surjective for any $R$. Finally, we describe $\theta^\#_R$ in
terms of the moduli space of Langlands parameters and use this description to
give an alternative proof of surjectivity in the tamely ramified case.
